100 Things Every Designer Needs to Know About People, 2nd Edition

11 Nine Percent of Men and One‑Half Percent of Women are Color-Blind

The term color blindness is actually a misnomer. Most people who are “color-blind” are not blind to all colors, but really have a color deficiency that makes it hard for them to see differences between some colors. Most color blindness is hereditary, although some can be acquired through disease or injury. Most of the color genes are on the X chromosome. Since men have only one X chromosome and women have two, men are more likely to have problems with color vision than women.

There are many different kinds of color blindness, but the most common is a difficulty distinguishing between reds, yellows, and greens. This is called “red-green” color blindness. Other forms, such as ...