Black cats hair turned white at the root in cold weather

Hi,





I found a black feral cat in the summer, got her attached to me, and didn't see her till winter. she was completely black, but now her hair has become longer (which is for the cold weather), and when i pet her I see that near the root, her hair is almost completely white. also her hair is not as black as it used to be.





I wanted to bring her into my home, but now i'm a little scared, and before doing anything, i wanted to ask your opinion on whether shes ok or not. 





So whats your thoughts?

Dont think theres anything wrong...i have an indoor only black domestic medium haired black cat. When i dig into his fur its very light and grey at the roots. The lighter hair also sticks out in his armpit area.

I'm not sure if this might help

http://cat-chitchat.pictures-of-cats.org/2014/05/black-smoke-cat-with-white-mane.html?m=1