Color blindness is the inability to perceive one or more colors; this may involve complete or partial loss of color perception. Most forms of color blindness occur more frequently in males as an X-linked genetic disorder. Color blindness is actually a collection of several abnormalities of color vision. The most common form is a red-green blindness, which affects about eight percent of the male population in the United States. Red blindness is the inability to see red as a distinct color, while green blindness is the inability to see green. A rare form of color blindness is the inability to see the color blue.