Grandma still doesn’t know that it’s ok to get the one with blue and orange rings though.

Right, but it’s still easier to explain “either green or blue”, and the colors are in rainbow order for a reason.

It’s not just for grandma, most everyone would have an easier time remembering the “working” or “fast” colors than having to think about Gbps or watts, myself included.

Assuming you know she needs green and orange rings from the device she bought on amazon last week?

Once the color system is established, I would expect device packaging and/or manuals to indicate the compatible colors.

But why are you defending it with novel solutions and colour grading schemes for something which could simply not be named the same thing because it isn't the same thing?

You can interpret the colors as naming. I mean, it’s similar with HDMI, DisplayPort, Bluetooth, Wifi, etc., they all regularly get new variants with new capabilities and compatibility restrictions. Naming each version something entirely different doesn’t solve the compatibility problem. It’s like saying HTTP/3 shouldn’t be called HTTP.

I have a bunch of USB-C cables. Some will fry things some won't. How will a naming convention help me keep track of them once they get chucked into in the basket under my coffee table