Well, I can chime in until someone with better info comes along.
Going from T to E has affected my hair color and texture. There are men who start going gray or losing their hair in their teens. I had a neighbor in his 30s who had a full head of gray hair. Though your graying may not -necessarily- be T related. Sorry I can't give more definitive answers. Also, I think there's a hormone called DHT that does stuff to hair, but I don't recall any details.
Don't be scared, just grow it long and be anime 🙂