See also the fantastic Color.jl, a Julia package with similar functionality. Makes very pretty IJulia notebooks! More info at https://github.com/JuliaLang/Color.jl or just run Pkg.add("Color") at your Julia REPL.
I'd be curious about a comparison of the capabilities and approaches of these two libraries. Color.jl got to be quite comprehensive almost by accident.
Color.jl is excellent! They have a few stuff we don't support like DIN99 colourspace related computations and colour deficiency support, on an other hand I think we have one of the largest dataset around, the features pages will give you a nice overview: http://colour-science.org/features.php
