Why is some of my gray hair growing out in my ntural brown color?

I have some gray that is growing out in my natural color. Why?Why is some of my gray hair growing out in my ntural brown color?
Well, that's a sign of aging.





But if you're young, gray hair can be caused by stress. Are you stressed often?





But gray hair can be caused pre-maturely from over-use of hair-care products. If you use a lot of products on your hair, Such as mousse, hair-spray, gel.





Also, it could just be natural highlights. I know my friend, she has platinum blonde pieces in her auburn hair. It's all natural, and she doesn't use any products. So, it's just the way her hair is.