deserving a very good answer- probably because your palms, which you'd apply and rub it in with are basically white for the most part. Those of us wih fair complexion will have mixed results. If you know anything about mixing colors, which I do from mixing paint, you'd understand this chemical reaction.
You know what really whacks me out-my chicken-shit of a damn upstairs nabe, has a perfectly good car w/ 4 wheel drive and wft he's do? stays put, tromping around upstairs like a damn waterbuffalo. My only way of cutting out of here'd be walking, and frankly, I haven't walked great distances in yrs.