What pigment is responsible for skin color?

The pigment that is fundamentally responsible for skin color is melanin. Melanin is a complex polymer derived from the amino acid tyrosine, and it is produced by specialized cells known as melanocytes, which are located in the basal layer of the epidermis. Melanin primarily comes in two forms: eumelanin, which can be either brown or black, and pheomelanin, which appears yellow or red. The amount and type of melanin produced by melanocytes determine the tone and shade of an individual's skin, as well as protecting the skin against the damaging effects of ultraviolet (UV) radiation from the sun. Increased melanin production in response to UV exposure leads to tanning, which serves as a protective mechanism.

Other pigments mentioned, such as carotene and hemoglobin, contribute to skin color but are not the primary determinant. Carotene, for instance, is a yellow-orange pigment found in certain foods and can affect skin color when present in larger amounts, while hemoglobin is responsible for the red color in blood and can influence skin tone, particularly in individuals with lighter skin. However, the primary and most significant pigment related to skin color variability across different ethnic groups and individuals is melanin.