What is a “color space?”

Well first you take some colors.

• red
• yellow
• blue

And then you arrange them, however you like, into some kind of space: //

What might a useful color space do? Well, just like the RYB color wheel, maybe it could help us predict how different colors will mix.

And lo, in 1931, an international team of experts got together in England and laid out a color space that does exactly that1. They used science and math. They called themselves the International Commission on Illumination (aka le Commission Internationale de l'Éclairage, aka the CIE), and they called their color space CIE XYZ.