Hering theory of color vision

n. The theory that there are three sorts of color receptors in the human eye, one sensitive to black and white, one to red and green, and one to blue and yellow. Included in the theory is that there is a chemical substance within each pair of cell types broken down by one color of the pair and built up by the other. Color blindness was thought to be due to the absence of one or more of these receptors.