Hot pink.
....if I was half my age. I'm very happy with my redish-brown dye I just started using. My normal color was medium brown with copious amounts of gray.

One of the first things I did after deciding to transition was (other than dye my hair) have my eyebrows done at a salon. Mine were large, bushy, and there was a very stubborn unibrow problem (I've shaved the center every single morning for 15 years!). The girl who did them was very friendly & had no problem working on men (or when I asked for a shape suitable for a man or woman).
I'll also say that NO ONE noticed!!

I mean, yeah I don't want everyone to know I'm transitioning, but it would be nice if SOMEONE of my friends or family noticed. The difference was huge to me! Most people just really don't pay attention to what other people look like.