Human skin color the liver. On lighter to medium skin tones, solar lentigenes emerge as small- to medium-sized brown patches of freckling that can grow and accumulate over time on areas of the body that receive the most unprotected sun exposure, such as the back of the hands, forearms, chest, and face. For those with darker skin colors, these discolorations can appear as patches or areas of ashen-gray skin. Melanin in the skin protects the body by absorbing solar radiation. In general, the more melanin there is in the skin the more solar radiation can be absorbed. Excessive solar radiation causes direct and
Champagne gene The dun gene is responsible for flat, diluted coat colors and vivid primitive markings. Bay dun is thought to be the wildtype horse coat color. Dun does not affect skin or eye color, but dilutes red pigment to yellow and black pigment to slate gray. Champagne horses with the dun gene will have slightly further-diluted coats compared to non-dun champagnes, and will always exhibit striking primitive markings, such as a dorsal stripe and zebra-like stripes on the legs. The silver dapple gene in horses does not affect the eyes, skin, or red pigment. Chestnuts are unaffected, but in bay, seal