Pigmentation is determined by the amount of melanin in the skin. Melanin is produced by specialized cells called melanocytes found in the basal layer of the epidermis. The two main types of melanin that influence pigmentation are eumelanin, which causes darker skin tones, and pheomelanin, which causes lighter skin tones. The amount and type of melanin produced are controlled by genetics, and influenced by factors such as sun exposure and certain hormones. Without melanin, skin would appear pale white or pink due to blood flow beneath the skin. Thus, skin color variability primarily depends on melanin quantity and composition in the skin.