5. Hair and its color are separate things.
Hair stem cells are what make hair. Pigment is made thanks to pigment-forming stem cells. They always work together; however, if either of them wears out, your hair changes its color. Nowadays researchers are trying to find out the ways that would help people slow down the graying process. Dyeing hides gray hair, but it does not solve the problem itself, though.
6. Your hair doesn’t turn gray — it grows that way.
It takes between one and three years for a hair to grow. Then it sheds and a new hair starts growing. As we age, our new hairs are likely to be gray. Whenever the hair generates, we have to reform the cells that form pigment. Unfortunately, they still wear out and makes your hair white.