Hair color refers to the pigmentation of hair follicles, which is determined by the type and amount of melanin present. There are two main types of melanin: eumelanin, which can be black or brown, and pheomelanin, which is responsible for red and yellow hues. The combination of these pigments results in a variety of hair colors, including blonde, brunette, black, and red. Genetics play a significant role in determining an individual's hair color, as it is inherited from parents. Environmental factors, such as sun exposure and aging, can also affect hair color over time. Additionally, many people choose to alter their natural hair color through hair dye or bleaching techniques for cosmetic reasons.