There are total color blindness and partial color blindness. Partial color blindness, i.e. Can see some color, is much more common than total color blindness, i.e. See all colors in black and white.

Among partial color blindness, there are two types: Those who have can't see the difference between green and red, and those who can't see the difference between yellow and blue.

According to studies, red/green color blindness is the most common type. It is passed on via a faulty colour vision gene on an X chromosome as a recessive disorder, which involves the confusion of red and green. Red often appear dull and indistinct to them; or orange, pale red, green, and brown all appear as the same hue.