[Quiet Man Cometh]

Could just have a few funny strands. Hair is never one uniform shade. my sister was making wigs for film at one point and the are never solid. Even light blonde wigs will have strands of brown and black mixed in.

Might have encountered a chemical or something in a few strands, or one patch got more sun than another. I wouldn't fuss over it unless it's something rampant, and closer to the top of your head. Hair that is already grown wouldn't be as reflective of current health but maybe something in the past.