Color blindness is not actually blindness at all. It is a deficiency in the way you see color. If you are color blind, it makes it difficult to identify certain colors, such as blue and yellow or red and green.
Color blindness is an inherited condition and effects more men than women. An estimated 8% of men and less than 1% of women have color vision problems.
Red-green color deficiency is the most common form of color blindness.
Much more rarely, a person may inherit a trait that reduces the ability to see blue and yellow hues. This blue-yellow color deficiency usually affects men and women equally.