Melanin
A skin pigment (substance that gives the skin its color).
Dark-skinned people have more melanin than light- skinned people.
Melanin also acts as a sunscreen and protects the skin from ultraviolet light.
Melanin is produced by cells called melanocytes.
It provides some protection again skin damage from the sun, and the melanocytes increase their production of melanin in response to sun exposure.
Freckles, which occur in people of all races, are small, concentrated areas of increased melanin production.