What pigment is responsible for skin color?

Melanin is the pigment primarily responsible for determining the color of human skin, hair, and eyes. It is produced by specialized skin cells called melanocytes and is found in varying amounts and types in different individuals. The type and amount of melanin influence skin color; for instance, higher levels of eumelanin lead to darker skin tones, while lower levels contribute to lighter skin tones.

Unlike other pigments, such as hemoglobin and carotene, which play different roles, melanin directly relates to pigmentation and protection against ultraviolet (UV) radiation from the sun. Hemoglobin is a protein in red blood cells responsible for transporting oxygen and gives a pinkish undertone to the skin, but it does not determine skin color by itself. Carotene is a pigment found in carrots and other vegetables which can impart a yellowish hue but is secondary to melanin in humans. Cholesterol is a type of fat found in the body and is not a pigment but contributes to various biological functions.

Understanding these roles clarifies why melanin is the primary determinant of skin color among the pigments mentioned.