Tanning takes place in the skin's outermost layer, the epidermis, with special cells called melanocytes. When exposed to UV-B light (short wave ultraviolet), melanocytes produce the pigment, melanin. The pinkish melanin travels up through the epidermis and is absorbed by other skin cells. When exposed to UV-A light (longer wave), melanin oxidizes or darkens. This is your skin's way of protecting itself against too much UV light.