There Are Several Types of Color Blindness
Because our color vision is based on an interaction of three color photopigments - red, green, and blue - a deficiency in any one can lead to color blindness. The photopigment affected will determine the type of color blindness you have.
Seen most often in men, this form of color blindness may leave you unable to see reds or greens. There are many variations: some see red and orange as green, some see red as black, and so on.
People with this form of color blindness cannot see blues or yellows. As a result, blue may look green and yellow may look violet or grey.
Total Color Blindness
With this extremely rare form of color blindness, everything either looks the same color or has no color at all. It is often accompanied by an intense sensitivity to light.