I read an amazing article once that described the representations of color at different processing levels in the human brain. For example, the 3 types of rods in the retina sense R/B/Y intensity, but at some point it is transformed into a different 3d representation with a R-G axis, a B-Y axis, and a greyscale intensity axis. There was some implication that this is information-theoretically optimal in some sense for representing images sampled from the natural world. Anyone know what I'm talking about?

The book you mention seems to cover similar ground: http://www.yorku.ca/eye/toc.htm