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Color Wheels Are Wrong (2011) (asmartbear.com)
95 points by charlieirish 5 months ago | hide | past | favorite | 76 comments



The article was clearly written by an enthusiast, but is a bit muddled. I see nothing in what he has written that supports the idea that Color Wheels are wrong.

Color wheels are, in essence, highly abstracted slices across the equator of a color space. Only two color wheels are commonly used: the RGB and the RYB (aka the artists color wheel). Color from pigments and color from light are two wildly different things, but easy to confuse. For its absence of green as a primary, CMYK can be understood as a version of RYB. Black is used not just because it is cheap but also to add opacity to the inks (printing inks are more like dyes... very thin and transparent).

The color opposites the author describes are red/cyan in RGB and red/green in RYB.

One property of these opposites is that they mix to neutral. For this, the RBG pair works best. The other property is that they are perceptually antagonistic, for which the RYB pair works best.

Interestingly, the perceptually antagonistic pair set (red/green, yellow/purple, blue/orange) were spoken about well before Newton placed these colors in a circle. Leonardo Da Vinco refers to them as 'retto contrario', literally exactly opposite.

The author asks 'why a wheel'? which is a good question, and the answer he gives is reasonable. But... Newton was the first to employ this device, and he did so almost certainly because the harmony structure of the musical scale was commonly visualized as a wheel, and Newton was keen to draw an analogy between music and color and harmony and the music of the spheres and god etc etc. He may have been the first physicist, but he was also an alchemist.

Color is a frustrating beast... so many different ways to understand the same thing: perception, physics, aesthetics, chemistry etc. Truly the seven blind men and the elephant.


I think CMYK can be seen as a practical adaptation of RYB for printing purposes


Did you read to the end? He givers a physiology-based argument for a color wheel with four primary colors.


This is like watching some preschoolers argue whether the rainbow has 4 or 5 or 7 colors. The arguments do not make sense at all because they are actually some form of opinion.


Well... I would say that you are half right. The whole notion of primary/secondary is very dependent on application, so your primary set would depend on your intended use. Psychology recognizes six primaries: red, green, blue, yellow, white and black.

The author presents a four-color primary set. It clearly has its roots in Helmholtz's color physiology, but I confess I don't quite understand how it would be used. For me, I would miss the important blue/orange pairing.


The problem is that yellow is much lighter than blue. If you look at a perceptual pseudo-cylindrical color space such as CIECAM02 or (OK)LCh, yellow and blue are not on the same wheel because they exist at different lightness levels.

So the author is correct that there are four opponent colors, but not correct that they can all be arranged on a wheel so easily.

Color spaces are three dimensional geometries, attempts to reduce them to two dimensions are always wrong just like every 2D map projection creates distortions.


This is, at core, a demonstration of the complex dimensionality of color.

Yellow is not lighter than blue, though I can understand why you say this.

In the hue, saturation and lightness (hsl) understanding of color, hue terms such as Blue/yellow and lightness terms such as light/dark are separate entities.

It is perfectly possible to have a blue and yellow of the same lightness value, but the yellow would be more dull. More dull = less pure = less saturated. The peak saturation to lightness of different hues is not consistent. Yellow is most yellow (ie most saturate/pure) when it is quite light. Conversly the peak saturationn of green or blue is in the dark range.

As you rightfully state, One key issue with the color wheel is that it is two dimensional. There does not exist a remotely complete color model that does not recognize at least three dimensions.

I am not dissing the utility of the color wheel, but it has application only to the ordering of hues.


green as a "primary", when it is a combination of blue + yellow, seems strange to me


No, they are not just a matter of opinion (although there is some small subjective element to it).

If our eyes somehow detected the exact wavelength of light directly then, yes, we would perceive a continuum of colours and it would be totally arbitrary how you divide it up.

But we don't. As the article says, we have a discrete set of cone types that divide our perception of colours up into clusters (albeit overlapping and fuzzy). For that reason, for most people with normal vision, a rainbow appears to have 6 main colours.


We have a discrete set of cones but they have continuous outputs so the space is indeed a continuum.

The 6 colors of the rainbow are arbitrary and cultural (I've always learned there are 7). There's no physiological reason we say orange is a color but dark orange isn't. We perceive more than 7 colors.


The rainbow as perceived by most humans has six distinct color peaks / bands that are noticeably distinct from each other. Physically it is an even continuum of wavelengths, but look at it with your own eyes and you will see clear banding. This is due to way retina information is filtered to produce color signals before being fed into the brain.

Why seven colors? Because Isaac Newton felt it must be 7 due to it being a more mystical number, so he shoved indigo in there.


> Newton, who admitted his eyes were not very critical in distinguishing colours, originally (1672) divided the spectrum into five main colours: red, yellow, green, blue and violet. Later he included orange and indigo, giving seven main colours by analogy to the number of notes in a musical scale.

> The question of whether everyone sees seven colours in a rainbow is related to the idea of linguistic relativity. Suggestions have been made that there is universality in the way that a rainbow is perceived. However, more recent research suggests that the number of distinct colours observed and what these are called depend on the language that one uses, with people whose language has fewer colour words seeing fewer discrete colour bands.

https://en.wikipedia.org/wiki/Rainbow


Clearly 7, because 7 is the most powerful magical number. That's literally the level of Newton's justification, who invented the concept of a 7-colored rainbow.

While we're here, one of my favorite unsong quotes, at roughly the same level of woo:

    > Then there was light.
    > 
    > Beautiful, multicolored light, ten colors, the seven colors of the earthly rainbow and the three extra colors you only get in Heaven. Ten colors corresponding to the ten sephirot and the ten fingers and the Ten Commandments and the ten digits of the number system and the ten pip cards of the Tarot and all the other tens in all the correspondences of the world.


Where does this come from? The Torah I first assumed, but then I say mention of thebtarot.


"Torah fan fiction" by Scott Alexander at unsongbook.com . The sephirot part is from kabbalah.


That makes sense, since it separates out green from yellow, which is where we have two cones close together in the spectrum (nominally green and red cones) and the most response and discrimination (humans are good at seeing greens).

This part is surely an error, though:

> So there’s no such thing as “red with a little green”—there’s just a less intense red.

This would mean that a monitor can't display orange (red with a little green).


Heh, meanwhile over here in paint world, I've been mixing red and green to make grey (specifically Royal Talens (362 Deep Rose) + (602 Deep Green)).

I think of orange as yellow + small amount of red, but hey.


Yeah, additive (light, monitors) and subtractive (paint) color systems work differently


I think you’re missing the point on orange. When I see aquamarine, I see blue and green at the same time. It feels like blue-green. Orange on the other hand looks and feels like a unique color, not red + green (although I know why that is). TFA is using physiology to explain why these color mixes are perceived differently.


Yes, but at that point in the article, it's clearly talking about the amount of red, green, or blue signal being picked up by cone cells, and thus the wavelength or mix of wavelengths, which is additive mixing. It's claiming that red plus some green (in terms of stimulation of cone cells) equals dimmed red, which is factually incorrect.

This part about "three filters" is overstated, I think, if based in fact at all. Presumably it's based on something the retina is known to do, but I hadn't heard before of red and green being preprocessed separately from blue, and given that we can see orange when presented with red and some green pixels, it's not exactly as stated.


> Ask any artist to explain how color works, and they’ll launch into a treatise about how the Three Primary Colors—red, blue, and yellow—form a color wheel

I doubt that. More likely that they look at you akwardly or say a joke and try to carry on.

Some artist couldn’t care less about colours. A sculptor thinks much more about shapes, a 3d animator thinks much more about motion.

A writer or poet cares a lot more about what connotations different colour descriptors carry. “The sky above the port was the colour of television, tuned to a dead channel.” doesn’t quite hit the same as just calling it grey, for example.

Painters have a much more intimate connection with colour. But instead of thinking in primary colours they will be much more familiar with the mixing of the pigments they use. (Cadmium red, cobalt blue, burnt sienna, etc) A print artist or someone designing figurines or design objects would think in terms of pantone colours. Someone doing thread painting with embroidery floss will think about DMC colour codes.

And then of course there are colourist working on movie and TV productions who would know all the article describes and more. It is their job to know.

I don’t know why an otherwise quite okay article has to start with this image of the dum-dum arist “launching into a treatise” of kindergarden level colour understanding. It feels a bit degrading, as if the author has low opinion of artist. (And certainly not considering the full palette of the arts.)


I'd mention the book Blue and Yellow don't make Green, which taught me that my minimum set of paints should be:

* A purple-inclined red (crimson) and an orange-inclined red (scarlet)

* A green-inclined yellow (practically speaking, "spring green") and an orange-inclined yellow ("yellow")

* A purple-inclined blue (ultramarine) and a green-inclined blue (cerulean)

* White to make light tones (don't worry about black)

And these let me get almost all the spectral colors because, I think, the pigment grains don't interfere and don't cause subtractive mixing (there was some sketchy explanation about light bouncing between different pigment particles before bouncing properly back from the canvas). There are gaps due to the lack of any pure primary color, which we basically give up on being able to buy.


> * A purple-inclined red (crimson) and an orange-inclined red (scarlet)

> * A green-inclined yellow (practically speaking, "spring green") and an orange-inclined yellow ("yellow")

> * A purple-inclined blue (ultramarine) and a green-inclined blue (cerulean)

> * White to make light tones (don't worry about black)

This is excellent advice for a painter, though I would not exclude black.

The six color you describe are, in essence, a warm/cool pairing of the three primaries. When I painted in color I used:

Cadmium red/alizarin crimson, lemon yellow/cadmium yellow, cobalt blue/Prussian blue


blueish red is a pain in the ass because there are not many pigments in that range that aren't "fugitive", meaning they fade in light. Alizarin fades fast. Last I checked a pigment called Quinacridone fits that spot on the wheel and doesn't fade.


> When I painted in color

I gather you've moved beyond that now. Probably wise, it's a lot of fuss.


> Blue and Yellow don't make Green

Many children were incorrectly taught that Red, Yellow and Blue were "primary" colours from which you could make any other colour: wrong. Fotunately we have better teaching now.

I like some of the comments here: https://nitaleland.blogspot.com/2005/10/urban-myth-blue-and-...


In my experience, artists have a very fuzzy understanding of color, even those who use it wonderfully. At art school we were taught 'color theory', almost all of which was hand-wavey fluff.

> instead of thinking in primary colours [Painters] will be much more familiar with the mixing of the pigments they use. (Cadmium red, cobalt blue, burnt sienna, etc)

Absolutely agree. A red is never just the abstract red, it is a cadmium red, alizarin crimson, rose madder etc.


It happens I was re-reading my sister's book about fabric ("Poetic Cloth") yesterday, and yeah, no mention of this idea of "Primary Colors". When she explains her practice she's basically just eyeballing it. Match a cloth or a thread against your target visually, hold them up to the light, that sort off thing. Which makes a lot of sense.


yeah, anyone that paints will care the most about other things, like which colors they actually have available, and the quality of the pigments. If you take, say, most single pigment reds that aren't very toxic, you'll see that they have relatively low coverage: Lay it over a dark color, and you aren't really getting red, but filtering the darker color with some red on top. Pure pigments however kind of mix into reasonable colors that more or less resemble what a color wheel will tell you, but many paints are reached through mixes, and mixing mixes is often not getting you the colors the wheel would predict: Chances are you are getting something pretty brown, with very low intensity. You can make fun tricks for students, like showing them two pairs of almost indistinguishable blobs of paint, but that mix to something different, because two of the colors were pure pigments, and the others a carefully made mess.

And then there's not just color, but finishes, and the body of the paint.

So yes, once actually talking colors in a real piece, while the color wheel is a very useful tool for determining pleasant schemes, just like in a website, your real primary colors you think about are never a bright yellow, a bright red, and a bright blue.


> while the color wheel is a very useful tool for determining pleasant schemes

Is it? To my eyes, opposite colors on the painter's color wheel are maximally unpleasant. Green/red, for example, is infamous for creating bizarrely strobing optical illusions, when placed adjacent to each other. Purple/yellow. Blue/Orange. Also horrible combinations. I don't find color triads to be particularly pleasant combinations either.

I'm convinced that it's some made-up Victorian pomposity that nobody bothered to contradict, because anyone who was an actual artist didn't use it. Much like the Victorian theory that we taste salty and sweet on different parts of our tongue (we don't).


It is. The color wheel says complementary colors pop, but it doesn't imply this is a good thing. It's up to the designer to create something interesting from the contrast, typically by not putting them directly together.

A sibling comment mentions the blue-orange movie poster trope, and this is an excellent example. Note how the posters use the two colors: large blocky areas separated by either a smooth gradient or a high-density area of interest.

Here's some other examples:

https://janabouc.com/2016/07/30/color-boot-camp-part-iii-com...

https://www.bhg.com/decorating/color/schemes/complementary-c...


Certainly blue/orange is notorious for making a dramatic visual effect:

https://tvtropes.org/pmwiki/pmwiki.php/Main/OrangeBlueContra...

whether that's a good thing ...


> Black is included as a money-saver

Since when were printer manufacturers concerned about saving the end user money? lol.

Black is included because if you mix typical dye based inks you do not get a black, you get this greenish looking thing that is clearly not quite black. A few here are old enough to remember when early color inkjets could only hold either the tricolor cartridge or the black cartridge (ex HP 500C).


Then you get oddness like my brother laser printer, that has seperate Black and CYMK toner packs, and you have to specifically choose 'black and white' if you want to use the massive black toner set for text rather than the tiny 'K' toner pack.


> Some of those frequencies we detect with our eyes, and the frequency determines its color

This is common misconception. It's not singular frequency of light that determines color, but the entire distribution of intensity over visible light spectrum.

And it is not one to one mapping from spectra to color either. In theory there are almost infinite spectra for each color.

So mixing red and green lasers might produce something appearing yellow(ish) despite the spectrum not containing any light corresponding to spectral pure yellow wavelengths.

As for the "art primaries", afaik it's not so wrong of a color model; it just is a reflection of common paints/pigments operate. Painters can not get nice spectrally pure pigments for primaries, not now and even less so historically, and so the color space of paints is significantly smaller than the entire human vision color space.


>> Some of those frequencies we detect with our eyes, and the frequency determines its color

>This is common misconception. It's not singular frequency of light that determines color, but the entire distribution of intensity over visible light spectrum.

Why can't it be both?

The CIE spectrum locus, which is a saturation plot for the visible spectrum, labels perimeter by monochromatic wavelength, yet the CIE color model is tri-stimulus (three primaries) with the plot providing helpful symmetry for calculating chromatic mixes.

Note that there's no contradiction in the language which regards a "spectrum" in the sense of physics with a model of mixed "primaries" in the sense the physiology of human vision.

As to the surrounding points in this thread regarding what does or does not constitute a logical color wheel, the arguments are too invested in labels for effects of a given medium, and lacking sufficient discrimination of context of media, application, psychology, history and science. Color is a subject wherein many seemingly divergent views can all be correct when regarded in specific narrow contexts.

I think there's an obvious bifurcation of understanding, between art and science.

Ultimately, the topic of color forces the thinker to confront the question that all understanding is purely psychological. The first step on a slippery slope towards this question is the observation that color is both as real as anything we experience, and that objectively color is a pure qualia. That people reliably atomize a perceptually smooth chromatic gradient into ROYGBIV is a true conundrum-- that we should so readily and implicitly partition a continuum seems characteristically linguistic, in the sense of counting, which is at once a form of pure vocabulary (naming) but also a system of reasoning (mathematics).

This conundrum prohibits coherent dialog about color topics because common thinking, such as immediate topic of the color wheel based on mixing primaries, ignores that the term "primary" has different connotations for additive versus subtractive media, so it can't distinguish that RGB (CIE) and RYB (classical artistic theory) are distinguishable taxonomically by observing the effect of silent (in context) "secondary" colloquially known as "cyan".

To be clear, by secondary I mean the negation of additive (projected incident light) primaries, colloquially known as RGB, which negation gives rise to secondaries CMY of the form –R, –G, –B. In painting the medium is inherently subtractive, incident light reflected by a medium. This gets confusing because "primary" in the taxonomy of color substantially predates the projector technology and the CIE model we now take for granted. Today "primary" should first mean the CIE vernacular because its model can explain painting and many other media, whereas the older vernacular of painting can't even explain itself, because it's not a science, it's merely a structuralist cataloging of particulars.

Understanding the physical properties of a medium is insufficient to generation of clarity. Arguments about the correctness of color wheels that don't scrupulously examine assumptions about the vernacular of qualia are ideological even when attended by a coherent physics of stimulus. We can't rectify contentions of color ideology with appeals to a narrow physics of any artistic medium. The science of the CIE avoids color names except as a sort of adjunct mapping just to be helpful for correlating conventions of vernacular with the spectrum locus. To the CIE, the primaries are idealizations of long, medium, short wavelengths that excite a normalized model for human retinal cone photoreceptors. It's the Munsell color system that truly bridges the gap from the CIE's science to aesthetics via a rigorous system of correlation of effects.

The takesway here is that arguments over the objective correctness of any color wheel are pointless.

But such arguments do strongly indicate (or illuminate, so to speak) that we regard color as profoundly real. This realization is interesting as it deeply troubles epistemology: any example of a profound reality of qualia disrupts the prospect that we can truly understand anything but ourselves. We are trapped in Plato's cave with no way out but a sort of divine resurrection (in the Christian sense) of thought. A large rock must be moved from the cave entrance by God to free the soul to fully manifest itself.


This topic has been written about in more depth by people who didn't try to work it out by themselves.

The classical artists color wheel is based on pigments. Printers use dyes. Screens use light. That's the whole reason why the primaries are different. The wheels are just tools.


Blue and Yellow Don't Make Green by Michael Wilcox covers the mechanisms behind subtractive colours (paints) pretty well. Also explains why it will never make a really bright green.


The way traditional artists think and thought about colors is definitely not in the shape of color wheels.

Traditional artists think in terms of palettes and of mixtures of colors on the palette. They also think about colors in relation to each other. They think of layering, and about the perception of the eye.

The point is, when you discuss colors as a multi-dimensional coordinate space, you already lost (from the perspective of the painter).

Painters will explore the medium they are working in for its capabilities. Is "dark on bright" (watercolors) or "bright on dark" (soft pastel) the way to go? Can I dilute and perform washes (watercolor), or will the medium break down (acrylic).

I can only recommend James Guerney's "Color and Light" book to get impressions.

Then again, if you do digital art to scren, or if you are printing things from a computer, you need to anticipate how the devices render your colors. This is where color spaces and coordinate systems for colors and how to translate between them becomes relevant.


> The way traditional artists think and thought about colors is definitely not in the shape of color wheels.

Slightly disagree. I find that knowing the location of the pigments on the rtyb wheel is a very useful skill. A color too saturated or too light? add its opposite!


> Every seven-year-old kid in America is taught that “the opposite of red is green” and “the opposite of blue is yellow.”

In Europe as a kid I was taught in art class the following opposite pairs instead:

red-green

blue-orange

yellow-purple

And these pairs were each said to make brown when mixed (I know, it's very different compared to RGB or CMY where the neutral color is gray)


Color is hard, but this article doesn't do it justice. Wheels aren't broken, perception is just weird and filled with all sorts of fun non-linearities.

The article begins to touch on color spaces, which is where I'd suggest curious folks to begin if they're interested in color.[0] The article fails to note the fact that MANY other color spaces have been invented in attempts to address the problems it mentions![1] OKLab is a modern one that may be familiar to folks here. Scroll down to some comparisons vs other spaces, it's a nice uniform circle again![2] (OK, maybe not entirely uniform. Color is hard.)

Tangent: Why the heck are there alpha-blended images in an article about color!?

[0] https://en.wikipedia.org/wiki/CIE_1931_color_space

[1] https://en.wikipedia.org/wiki/List_of_color_spaces_and_their...

[2] https://bottosson.github.io/posts/oklab/#munsell-data


Everything in the article, from start to finish, seems to make perfect logical sense.

The problem is: to me, that perceptual colour wheel at the end does not appear to be perceptually uniform at all. The left hand side (yellow->green->blue) appears to vary far less than the right hand side (yellow->red->blue).

To me, the artist's one at the top looks most perceptually uniform, despite not being quite right from a physics perspective. The physics based one, with red/green/blue and yellow/cyan/magenta equally spaced is somewhere in between for me. This probably explains the myth of yellow/red/blue being the primary colours – they appear most perceptually different.

So why is that so if, by the sensible reasoning of the article, the wheel at the end should look most uniform? I don't know the answer to that. Maybe it's due to one of those later layers of processing mentioned? Maybe the non-uniformity is just baked into our brains for some evolutionary reason, to do with colours commonly encountered in the wild?


It's a shame the article doesn't go deep enough to encounter perceptual uniformity. In short, the human visual system is strongly non-linear. We perceive more greens than blues or reds. None of the color systems mentioned in the article (including the CIE 1931 chromaticity diagram at the end) are perceptually uniform. The 1976 color spaces (CIELuv and CIELab) were introduced as an attempt to deal with this, and there's been many other attempts since.

My favorite is OKLab:

https://bottosson.github.io/posts/oklab/


> We perceive more greens than blues or reds.

As I said in reply to the sibling comment, this is essentially the opposite of my point: it seems to suggest that green should take up a disproportionately large part of the colour wheel (in fact, that's what the article's suggested wheel at the end does), but I'm saying it should take up less. But, as I mentioned in my other comment, an experienced perception of green looking similar to physically nearby colours is not necessarily related to our ability to "perceive more greens".

I haven't seen OKLab before, thanks. But it seems to be more about the perceived lightness of different hues, which is something different again.


You're right, I have it flipped. We see fewer greens and more blues.

https://en.wikipedia.org/wiki/Color_difference

https://en.wikipedia.org/wiki/Color_difference#/media/File:C...

You probably be more interested in or CIELab. OKLab builds off this and tries to fix lightness.

https://en.wikipedia.org/wiki/CIELAB_color_space

The Munsell Color system is also pretty cool.

https://en.wikipedia.org/wiki/Munsell_color_system


Your intuition is right, and can be explained by looking at both the visible spectrogram and also the CIE diagram. In the former, what we call green takes up an inordinate amount of the spectrum. In the latter, green clearly takes up the largest amount of area of any well defined color.

Your eye is most receptive to green, in both the narrow and broad sense. The absolute peak is a green, and of any reasonable, well defined broad grouping of spectra, the greenest one is the one your eye will be most receptive to.

Also interestingly, the two colors that dovetail into colors we cannot see on either end, red and violet, we are the least receptive to.

You can see this play out in real survey results from XKCD: https://blog.xkcd.com/2010/05/03/color-survey-results/


> Your intuition is right ... Your eye is most receptive to green ... of any reasonable, well defined broad grouping of spectra, the greenest one is the one your eye will be most receptive to.

Hmm, but doesn't that disagree with my intuition? Unless I misunderstood you?

I'm saying green looks similar to nearby colours so should take up less space on a perceptual colour wheel (e.g. blue and green look much more similar than blue and red to me, so blue and green should be much closer to each other). But you're saying we can perceive many shades of green, presumably with the implication that it should take up more space on perceptual colour wheel.

That xckd article seems to agree with me: a huge chunk of the physical colour space is simply lumped into "green", rather than given lots of different names at you'd expect if different bits appeared visually distinctive.

In fact, this all is not necessarily a contradiction: perhaps we can distinguish between extremely similar shades of green, better than other colours, but experience even very different shades of green as feeling subjectively similar.


This was a good explanation - they simplify at points, but make it obvious they're doing so, which I'm fine with.

I would have liked to hear more about how the artists' color wheel came to be. It's a model, after all, and models don't have to be true as long as they're useful. The RYB color wheel is definitely not useful for setting colors in CSS, but as far as I know, the story goes something like this:

Before today's industrial processes, the colors of paint you could make or buy were those one could make from natural ingredients, for example cobalt for blue if I remember correctly. Artists and their suppliers noticed that if you had red, yellow and blue paint, all of which one could make from the materials available, then you could mix them to make any color you wanted (possibly with some white or black added to lighten/darken, or tint/shade if you're being pedantic). Further, you could make a lot of colors by mixing at most two of these colors, and it was purely the proportions of the mix that mattered, not the raw amounts.

So these got called "primary" colors, and it was natural to represent them in some way - to the engineer, a triangle seems like an obvious choice where the mix with 25% red and 75% blue lies 0.25 along the line from red to blue. Artists chose a circle instead, which is really the same model (mathematicians would say it's a topologically continous deformation from one to the other). At the time, the color wheel model turned out to be useful, and so it stuck around and got taught in art schools.

Magenta, Cyan and Yellow would have done just as well as starting points, but were harder if not impossible to get from the natural materials used at the time.

On the other hand, orange or brown as a starting color would not have got you the same mixing abilities as far as I'm aware. Brown is an interesting data point on its own because you can make it by taking orange and shading with a small amount of black, but you can also make it by taking orange and adding some blue (among many other ways), so now you're using all three primaries and fall off the color wheel. And that's before we talk about perceptual brightness and gamma correction and all that.

Red, Green and Blue on the other hand is a useful starting point for things that emit rather than absorb light (with similar but different caveats).


FWIW, I was exploring teaching color in K-2 using spectra. Here's[1] an old development snapshot, showing a color "wheel". Intent was a correct 3D perceptual color space (that snapshot isn't quite it), coupled with perceptual ("color") and physical ("light") spectra. Sort of the old art-school teaching from Munsell, but able to deal with materials and light. Absent an existing pedagogical perceptual color space (pedagogical: one without lots of "first thing you notice" features that are all bogus model artifacts), I kludged CAM16UCS with JzAzBz hue linearization and tweaks.

The author isn't wrong about current color instruction having dreadful content and outcomes. Ask first-tier non-astronomy physical-sciences graduate students what color the Sun is, and you commonly hear answers like "it doesn't have a color" and "it's rainbow color". Kids attempting to apply the models taught to their paints and pens and programs get... mixed results.

[1] https://imgur.com/a/zOtxQwe


The Sun is yellow because the sky is blue.


> Ask any artist to explain how color works, and they’ll launch into a treatise about how the Three Primary Colors—red, blue, and yellow—form a color wheel

I don't think the author asked _any_ artists how color works before writing this line.


From the article:

//(Diagram) Josef Albers, Folder IV-1 Actually, the squares are exactly the same color! The surrounding context dictates the perceived color, on top of all that wavelength-physiology we just did.//

There's a difference between a color and a perceived color?

To add to the absurdity, I don't think you can argue that the example presents the same stimulus!

Maybe the author regards the term "color" as having a meaning in the sense of common-sense, except in this sense the common-sense sense of the sense has no common sense.


On what planet is blue the opposite of yellow? I was taught that blue is opposite of orange and yellow opposite of purple, which is symmetic.

I found the whole article a bit rigid and huffy. The standard color wheel and CMYK are just different ways of reducing color to basics from which other colors can be made. The watercolor set we used in elementary school is another, just less economical.


>If you are asked to imagine “a green with a bit of red,” nothing comes to mind.

Anyone else see an apple with that colour in their mind?


For a page about color, most of the images are sure washed out. Their white is visibly gray. I don't figure out why though. When you open up the images in a new tab they look fine, and I don't see opacity or a color transform in the CSS. It looks pretty bad though.


> In fact A and B are the same color (#787878), but you can’t see it even when you know this. To prove it to myself I had to open this picture in an image editor and actually move one square over another to see it was the same.

Looks like they're actually both #434343...


Goethe... his contemporary Schopenhauer has interesting notes on color theor, from an historical perspective

Wittgenstein also wrote some interesting notes on color. Both are more interesting than this blog post.


I'm not sure that I'd get "color wheels are wrong," from that, but it is a really good article on color perception and management, which is a huge topic.




Some interesting facts included, but a terrible presentation. The tendency to claim certain tools or visualizations are “wrong” for such a complex topic is a sign of a very incomplete understanding of the subject matter. We often learn about things in phases. Step 1: “Use this simple abstraction”, step 2 “actually that abstraction is ‘wrong’, here’s the real details”, step 3 “actually that abstraction was sort of right, in the appropriate context, with these caveats, as a tool, etc”.


Interesting. I didn't expect this kind of content from a blog I usually associate with giving startup advice.


That's probably why it's such a bad article.

Symptoms of a potentially bad article include:

1. Someone writing about something they are interested in, but which is outside their realm of expertise

2. An article which starts with a strawman

3. An article with a "hot take" title

The definition of a color wheel is "an abstract illustrative organization of color hues around a circle". It's meaningless on its face to say that an abstract illustrative organization of anything is "wrong" in any objective sense.


As an artist I have a perspective on color from a pragmatic (as opposed to theoretical) point of view. Visual artists use materials like paints or inks applied to substrates. These all are exploiting subtractive color, primaries are complements of additive color, CMY vs. RGB.

The standard color wheel interleaves CMY with RGB, which sets up useful symmetries and complementary relationships. But of course, the color wheel is really a color cylinder, or set of cylinders when color properties other than hue are considered. Color saturation and value are crucial to artistic work, but when these additional dimensions are accounted for it's no longer the simple model the basic color wheel portrays.

Color classification systems emerged in the 20th century and over time evolved into the highly rigorous regimes codified by the International Color Consortium. Everybody is familiar with ICC profiles and their uses. I can't say I have a thorough understanding of them, I'd guess relatively few people do.

Artists don't have handy ICC profiles to guide creating a painting or print. They learn how to mix colors mainly by trial and error. However the paints and inks are precisely formulated by manufacturers who very much understand the science of color. This precision results in product constancy which makes life far easier for artists. With experience they gain an intuitive "fix" on particular colors and their locations on the extended color wheel.

To make it even more convoluted there are metallics, gold, silver, copper, etc. and the range of man-made iridescent and interference pigments. These "colors" aren't easy to merge with even multidimensional color "wheels" (or matrices). Nonetheless, people typically interpret these pigments as colors.

A subtle factor is opaque vs. transparent color effects. These aren't mutually exclusive, but in "pure" form are distinct. Opaque colors may be mixed to form an intermediate color, but at lower saturation and value. More than not this is how people are taught to manipulate colors often in accordance with the basic color wheel.

Transparent colors may be mixed like opaques, with somewhat similar results. However, layering transparent colors potentially produces extended effects. While both opaque mixing and layered color are subtractive, layering can combine in several ways producing multiple "virtual" colors modified by filtering effects of layers.

Any color wheel, or multidimensional matrix, is unlikely to accommodate the numerous ways colors combine or mix, or non-color colors. Artists use color wheels or more complex structures to gain pragmatic info about the colors they're using and predict results of manipulations. In any case, most real-world paints, inks, etc., don't behave like pure colors. A color wheel is only valuable as a pragmatically useful tool.


> Artists don't have handy ICC profiles to guide creating a painting

There's some paint app which uses pigment spectra and a physics model for blending and layering. I don't recall now whether/how it shows you that underlying spectra and such. If students did have pigment profiles handy as a guide, how might one imagine using that to better teach color?


I'm not familiar with an app showing spectra of pigments as used in painting, etc. Some high-end printers (plotters) incorporate spectrophotometers to measure properties of colors, but that's a highly controlled use of colorants.

In contrast, a painter can use a color in thick or thin layers, mixed with white, or clear medium, among other variations. And pigments can work differently in oil vs. acrylic vs. watercolor media. The spectrophotometric properties of a pigment change depending on usage so the information gleaned from measurement would probably not be that useful.

OTOH some manufacturers offer visual color mixing guides that can be helpful to artists. Here's one I've used from time to time: https://goldenartistcolors.com/mixer/acrylic?tab=color-syste...

This offers matching artists colors to RGB or CMYK specifications.


> app

I failed to quickly find the painting app I'm trying to remember. Though there's FocalPaint[1] (12 channel multispectral). Maybe it's Rebelle[2]?

It looks like there's unfinished work[5] for Krita? Mixbox[6] is related, but avoids actual spectra.

> mixing guide

Neat. ColorMixingTools[3] is similar, with a drop2color and color2drop, and online[4] and derived apps.

[1] https://www.focalpaint.com/p/focalpaint.html [2] https://www.escapemotions.com/products/rebelle/about [3] https://zsolt-kovacs.unibs.it/colormixingtools https://zsolt-kovacs.unibs.it/colormixingtools/cmt-drop2colo... https://zsolt-kovacs.unibs.it/colormixingtools/cmt-color2dro... [4] https://sensuallogic.com/paintmaker [5] https://invent.kde.org/graphics/krita/-/merge_requests/1783 https://krita-artists.org/t/paint-like-color-mixing-kubelka-... [6] https://github.com/scrtwpns/mixbox


I wish they sold cmyk crayons and watercolors for children.


I used CMYK (+white) tempera colors in primary and middle school, and so are my kids. Example: https://www.amazon.com/Giotto-Box-Tubes-Tempera-Extrafine/dp...


I think you would then have to crayon with a pointillist technique in order to achieve additive mixing.

Having said that, the Wikipedia page claims CYMK is subtractive:

https://en.wikipedia.org/wiki/CMYK_color_model

But it shows magnified halftone and it looks like pointillism. The page "Pointillism" says "Pointillism is analogous to the four-color CMYK printing process [...] Televisions and computer monitors use a similar [RGB] technique [...] subtractive mixing of the pigments is avoided."

https://en.wikipedia.org/wiki/Pointillism

I suspect the CMYK article got it wrong. Or did it? Clearly where CYM overlap we get near-black, not white.


Subtractive color is where you mix the primaries to get black, which is what CMY does. c.f. additive systems eg RGB where you add primaries to get white


I know. The fact that CMYK printing (or halftoning generally) uses dots implies a sort of hybrid system. "What appears as cerulean is actually a blend of cyan, magenta, yellow and black, as magnification under a microscope demonstrates." Well, the magnification shows overlapping dots, and the result appears as stippling in yellow, green, red, cyan, and black (and white between dots).

I don't think CMY crayons (or paints) would work, although the idea is entertaining. Maybe I'm wrong and it all hinges on obtaining a good magenta, which would then mix with yellow to give red and mix with cyan to give dark blue. This is apparently the case with printer inks, but it blows my finger-painting toddler mind, and I still think trying this out with a magenta crayon will lead to disappointment. (I'm going to look and see if I've got one, but I think they aren't usually sold. I'd probably have to paint with inks to try it.)

Edit: found some suitable-looking water-soluble crayons, did my best to mix blue and red via approximate magenta, cyan, and yellow, got lavender and peach. Too approximate.


Once we can model the inner workings of the eyes, and optics of the physical world on "small" scale, accurately enough, it will be possible to collect lots of data on data. Consequently, an analysis of whether two invididuals of same skin color, medical profile (e.g. no cataplexy) and proportionally similar facial and body anatomy, that have near identical eyes, see colors differently in a laboratory environment. How can we make them to see colors differently by only making optical changes to the environment? Will we discover that species, age, sex or some mutation affects their "sensitivity" so that for some factors slight change can make colors seen differently?

The pattern: Control experimentally (IE slightly opposed to "statistically" where done afterwards) for the confluencing factors that seem obvious but you are uncertain are complete (IE can you "find / make two test-subjects significantly more identical with a reasonable amount of effort?"); choose something that can be observed in laboratory setting by the invididuals such that you can replicate the same environment for both of them; and now study this changing this thing the invididuals supposedly observe similarly at least in this and that environment by only changing the observed thing; seems to be more general, EG applicable to taste, smell. This may also actually not provide that much new scientific information.

What is the best neuroimaging definition for color that can be made? IE, a program that gives a probability of what seeing colors differently causes in the brain. I think we should, because our intuition is to teach children that animals also see colors at least partially, have the program be such that it is reasonably species agnostic. Surely the patterns one will need are out there...

Yet, it turns out to be more likely that we will end up with different definitions for all bugs and all big land animals or something similar. Then we would want to turn that into two different vocabularies. But we realize that how MUCH DOES EVERYTHING MAKE SENSE once we go that route and what we can see will no longer be what defines how we speak. The Urdu decided to base their vocabulary primary on this and that qualia research and the Latinists have developed a thousand times larger dictionary from the fact they prefer to highlight small taxonomical details even when the effect is small, and are now proposing based on neurological twin study of the differences between these two groups a new addition to the Esperanto language for describing how the musical experiences of speakers of both languages differ. Sixteen years later Urdu and Latin both have developed many new layers on top of their descriptions of the Esperanto research.

What new artifical languages will qualia research give birth to?

Will homoiconic programming languages have an application in cybernetics EG the program modifying it's internal structure based on how an implant detects your definitions and other patterns in thinking to change? And actually, what is the cybernetics of this: when a person given implant that reads and writes into their consciousness "need" to explicitly communicate that "No, I want THIS thing, THAT is my expression self, not what you the implant will read" to prevent "bad" loops?

Will these sorts of languages converge?

The language that "universally" describe "baseline" human experience are a sort of exit condition that prevents an endless recursive complexity from drowning us. I believe that for the sake of sanity once we have the cybernetics to ascend this should be kept as separate language aside the new languages that might araise, which could be launched from dead languages. This will probably occur naturally because the group that does not have cybernetics will retain their tongue; but imagine getting ripped of your cybernetics and due to your lack of knowledge of the baseline language being in a state of linguistic disability.

DNA modification may lead to the baselanguage rupturing, EG the babies who as I wrote this on 2024-07-12 were inside their mothers might have few who have been modified to gain a vision that also expands their gamut, or least alters it. This one could argue will not be a problem because we have always had color blind humans: but color blindless has always be a problem; and DNA guaranteeing perfect eyesight at cost of altered but not disable color perspection is NOT a maldaptive mutatition.

There is another safe anchor, more powerful than retaining baseline language, called computability theory. For the moment, no sapient creature on earth has even approached this, but eventually computational limits will force different languages arising from hopefully endless storms of the conscious experiencs to converge. If the irony that the AI zombie problem exists in philosophical literature is put aside, eventually with (if) multiple SAIs are sitting around Tellus and Milky Way talking to each other and modelling what is happening in the other's brain, they might reach a state where the rational action is to start unifying many languages speaking of the same topic instead of languages of qualia on top of each other. It might as well be that they are all versions of the same successful blueprint for being a SAI and there is not much difference in their "minds" because any would be an inefficiency.

Half of this is meaningless, but only because I had several things to express and don't stress about being wrong.


2011


Obligatory XKCD "Evolution of my understanding of color over time" https://xkcd.com/1882/

I'd say this article is around a half of the way down the panel




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