What is primarily responsible for skin pigmentation?

Melanin is the primary pigment responsible for skin pigmentation. It is produced by specialized skin cells called melanocytes, which are found in the basal layer of the epidermis. The amount and type of melanin produced in the skin determine an individual's skin color. There are two main types of melanin: eumelanin, which is dark brown or black, and pheomelanin, which is yellow or red. The production of melanin can be influenced by various factors, including genetic predisposition, sun exposure, and certain hormonal changes.

In contrast, while carotene can contribute to skin color by providing a yellow or orange tint, it is not the primary factor in overall skin pigmentation. Hemoglobin, which carries oxygen in the blood, can affect the color of the skin but does not determine standard skin pigmentation. Cholesterol plays a role in various bodily functions but is not associated with pigmentation in the skin. Thus, melanin is unequivocally the main determinant of skin color variations among individuals.