What alleles cause color blindness?

The most common type of color blindness, red-green color blindness, is caused by mutations in the genes that code for the red and green cone pigments. These pigments are located in the cone cells of the retina, which are responsible for detecting different colors of light.

The genes for the red and green cone pigments are located on the X chromosome. This means that color blindness is more common in males than in females, because males have only one X chromosome while females have two. A male only needs to inherit one mutated copy of the gene to be color blind, while a female would need to inherit two mutated copies of the gene.

There are other types of color blindness besides red-green color blindness, but they are much less common. These other types of color blindness are caused by mutations in the genes that code for the blue cone pigment or in the genes that control the way the cone cells process color information.