Color Spaces

Leave it to human biology to be non-uniform and resistant to being easily mapped to a format computers want:

This may seem all like a pointless transformation, but there is a good reason for doing all this nonlinear mapping. The human eye is not a simple detector of the power of the incoming light – its response is nonlinear. A two-fold increase in emitted number of photons per second will not be perceived as twice as bright light.

What does it mean?

Linear encoding has the same precision of light intensity everywhere, which accounting for our nonlinear perception ends up having very quickly increasing brightness at the dark end and very slowly decreasing darkness at the bright end.