When I was younger I dyed my hair, but when I grew my beard I had to stop (my facial hair has ginger and my eyebrows are brown...didn't really go with the blue/black I was dying my hair). My hair has grey in it, but I shave it now
But I think there is nothing worse than older guys trying to look younger. A guy in my hockey team who is in his 40s (not old, by any stretch of the imagination) turned up to training with his hair dyed brown. And it was a terrible brown. Ugh. I think he learnt from his mistake and has gone back to his normal S&P (which really suits him).