Jack Black’s been busy working on new Ben Stiller movie,Tropic Thunder and, according to Black, the hair was part of Stiller’s vision. “It's his choice,” said Black. “To be fair though it's usually much blonder. The roots are growing out because I'm done with the hair. Well, I still have a couple more days of filming, but I'll be wearing wigs the rest of the way out.” Seriously dude, go find the…