Why color varies in hair of different people and why all the hair colors turn into white at oldage?
Original colour of Hair is white.
Hair color is determined by two types of pigment, eumelanins and pheomelanins, which together produce all the natural hair colors seen in humans. (“Melanin” is the basic term for any pigment, or coloring, in the hair or skin.) Pheomelanins produces the color red, and eumelanins can produce either black or brown pigments.
Eumelanins determine how dark or light the hair will be. A person who produces very little brown eumelanin will have blond hair. Low concentrations of black eumelanin will result in gray hair. Lots of black or brown eumelanin will result in darker hair.
Everyone has some pheomelanins (reddish) coloring in their hair as well. A person with true red hair will produce a high concentration of pheomelanins.
Simply put, hair become white (its original colour) when the hair follicles stop producing melanin, specifically the eumelanins and pheomelanins discussed above. Each of us is born with a limited number of pigment cells in our follicles. The precise number is genetically determined. As we age, pigment production falls off and then stops, which results in gray hair. Poor diet, smoking and certain illnesses can speed the process of pigment loss and result in premature graying.Grey Hair may turn into white, when melanin production completely stops.