LAB Color Space

http://en.wikipedia.org/wiki/Lab_color_space

I like the idea of color spaces with imaginary colors...

But here is the best part:

The nonlinear relations for L*, a*, and b* are intended to mimic the nonlinear response of the eye. Furthermore, uniform changes of components in the L*a*b* color space aim to correspond to uniform changes in perceived color, so the relative perceptual differences between any two colors in L*a*b* can be approximated by treating each color as a point in a three dimensional space (with three components: L*, a*, b*) and taking the Euclidean distance between them.


If a saturated green is viewed until the green receptors are fatigued and then a saturated red is viewed, a perception of red more intense than pure spectral red can be experienced. This is due to the fatigue of the green receptors and the resulting lack of their ability to desaturate the perceptual response to the output of the red receptors.^[2]
 

 

At Walt Disney World, Kodak engineered Epcot's pavement to be a certain hue of pink so that the grass would look greener.