Question: why do peoples hairs go grey?

Laura Soul answered on 12 Mar 2013:

Its because of a pigment called melanin, you might have heard of this pigment before. Everybody has it in their skin, when we go out in the sun it makes our skin produce more melanin and that’s why we look more tanned sometimes. Your hair is made of a special protein called Keratin, at the base of each of the hairs on your head you have a cell that makes new keratin molecules and adds them to the base of your hair so that it grows. Next to this there are also cells that make all the types of melanin and they put it into the hair as it grows and this stains it brown or black or blonde or ginger or whatever colour your hair is.

As you get older the cells that make melanin die and don’t grow back again so there is no melanin going in to the hair so it just stays grey. The age that you are when this happens is to do with genetics so you will probably go grey at the same age your parents do.