Colour blindness is a condition where the eyes have trouble distinguishing certain colours. Most people have either red or green colour blindness. Blue colour blindness and monochromatism, a condition in which a person sees only black, white, and grey, are very rare.
Most people have mild forms of colour blindness that don't interfere much with their daily lives. 8% of Caucasian men and less than 1% of Caucasian women have either red or green colour blindness. This condition is rare among people of Asian, First Nations, or African descent. Colour blindness is divided between inherited and acquired kinds.