Uhh... good question. The majority of my facial hair (if you can call it that) is white blond. I was also blond as a child, but my hair has slowly darkened into a reddish brown with blond patches (that mostly show up in the summer). Nine months on T is when I noticed that a few hairs in my sideburn region had turned a darker brown. In looking at my leg and arm hair, it seems that it is actually two-tone (like my head hair), with some of the hairs extremely blond and other hairs a darker brown. Go figure.
The way thing are going, this beard growing thing is gonna take *forever*