The Most Common Form of Color Blindness To someone with the most common form of red–green color blindness, these two photographs look almost exactly the same. People with this type of color blindness have normal blue-sensitive cones, but their other cones are sensitive to either red or green. Because of the way red–green color blindness is genetically transmitted, it is much more common in men than in women. About 8 percent of the male population is born with red–green color deficiency, and about a quarter of these males experience only the colors coded by the blue–yellow cones. People who are completely color blind and see the world only in shades of black, white, and gray are extremely rare (Shevell & Kingdom, 2008).

(both) PicturesWild/Shutterstock