I did an 07 s550 w lorenzer kit & asanti 22's, it was white & we did the wheel centers black & the whole lip white... looked totally sick.... those cars are cool too because doing a drop on it is all done through electronics....
painted lip can look sweet, would just think that if you do the rim all one black tone it may look cheap, like someone sprayed it with a can.... wanna really do something sweet? make the center semi flat lower gloss & the lips high gloss, then it'll look sick rather than cheap, just my opinion... all black, but with contrast too...
my chrome lips have a few tiny marks & I've been contemplating painting them too, I would do the centers black pearl to match my fx & the lips just gloss black & black out all the other trim on the whole thing maybe... just a little contrast will be the difference between gorgeous & cheap looking I think... look more classy & custom to me...