People who cannot tell all colors apart are said to be color-blind. Most color-blind people can see yellows and blues, but confuse reds with green. It is very rare for a person to be blind to all colors, but they may see everything in shades of black, white and gray. It is interesting to point out that many color-blind people don't even realize that they are color-blind, they don't know that the colors they are seeing and naming are not the actual colors that people with normal vision can see. This can be dangerous when a color-blind person confuses the red and green of a traffic light. Color blindness is thought to be inherited and although doctors have tested color blindness, there is no cure to treatment for it. There are four cards here, and each has two colors. Which card's colors do you think a color-blind person can tell correctly?
Red, Green Green, Yellow Red, Brown Brown, Yellow