How do people have different coloured hair?

People have different colored hair primarily due to variations in the type and amount of melanin produced by melanocytes in the hair follicles. There are two main types of melanin: eumelanin, which can be black or brown, and pheomelanin, which is yellow or red. The combination and concentration of these pigments determine an individual's hair color. Genetic factors play a significant role, as specific genes regulate melanin production and distribution, leading to the diversity of hair colors observed in the population.