Steering Wheel Fade

I have a 99 328 with a black steering wheel. The leather around the outside is worn away from hand contact over the years. It has turned a sort of brownish nasty color. It doesn't come off with normal leather cleaner. I think there is some sort of film protectant over the leather or something. Anyone have this issue or know of a product that might help restore it?



Thanks

Steering Wheel Fade