For parents, unruly children are the obvious cause of gray hair. To scientists, the situation is more complex. The matter is an issue of Genetics and aging. Melanin, a chemical produced by specialized cells within each hair follicle is responsible for giving hair color. Different types of melanin are responsible for different types of hair color, enumalinin for brown or black hair and pheomelanin for yellow or red hair. The type of melanin an individual has is controlled by pigment cells that are in turn, determined by genes. as we age the pigment cells at the base of our hair follicles stop producing melanin without the the chemical our hair turns white. The body has no central source of melanin, such as a gland: the chemical is produced for each strand of hair. That is why hair tends to go gray individually.