you can get vinly dye at the auto store and paint them. Heck, that's that ford does anyways to get other colors such as that hideous maroon that they had several years ago.
back in 95,96,97 or something, they actually offered two tone door panels that where black on top and grey on bottom. You can call stangparts and they should have them, but then your rear inside quarter panels won't match.
I was in the same dilemma as you. I just painted my door windows switch panels and door handle panels black. Looks a hell of alot better. Or you can just buy black ones from the dealer.