Function of skin pigment. Melanin is a naturally produced polymer found in a multitude of locations in the body, from the eye and ear, to the brain and skin. Each different location contains a different variety of melanin, such as neuromelanin in the brain, and eumelanin and pheomelanin in the skin.here reference is made to melanin in the text, eumelanin is implied. It is known that the melanin in the skin acts as a pigment, but the importance of melanin in most of the other organs is not well understood.