Why do we have hair color?

Hair color is caused by the pigmentation of hair follicles due to two types of melanin: eumelanin and phaeomelanin.If more melanin is present, the color of the hair is darker; if less melanin is present, the hair is lighter. Levels of melanin can vary over time causing a person's hair color to change or become gray because of loss of pigmentation.It is possible to have hair follicles of more than one color.