Oranges seem to be of a brighter yellow than that of lemons. Many color blind people cannot tell whether a woman is wearing lipstick or not. Disturbances of color vision will occur if the amount of pigment per cone is reduced or if one or more of the three cone systems are absent. Although defective color vision may be acquired as a result of another eye disorder, the vast majority of color blind cases are hereditary - present at birth. The gene for this is carried in the X chromosome.
Color blindness is rooted in the chromosomal differences between males and females.
Females may be carriers of color blindness, but males are more commonly affected. Color blindness is a malfunction of the retina, which converts light energy into electircal energy that is then transmitted to the brain. The cones are responsible for encoding color. Normal persons are able to match all colors of the spectrum by mixtures of only three fundamental color sensitivities. Hence, the huge variety of colors we perceive stems from the cone cells' response to different compositions of wavelengths of light.