A new concept of retinal colour coding.

A theory of retinal colour coding based closely on recent anatomical and physiological results is presented. Opponent colour channels are shown to be an inevitable result of any randomly distributed retinal cone mosaic, the structure of red-green opponent colour channels remaining uninfluenced by a predominance of "red" or "green" cones. These findings circumvent the conflict between anatomical results with more "green" than "red" cones and psychophysical estimations with more "red" than "green" cones. The effect of receptor compression and opponent colour transformation on colour perception is investigated. Non-opponency of pure green and pure red could be attributed to receptor compression, the Bezold-Brücke phenomenon, however, to the antagonism of "red" and "green" cones within the receptive field surround of red-green opponent cells. The fundamental colours are estimated to be supersaturated violet, yellow-green and yellow-red.