I'd assume the chances of them not noticing that you painted the wheels is fairly slim. Not impossible, but slim.
Either way...given the price of OEM wheels I would not want to find out the hard way, or that would be the worst $2500 decision you ever made.
Conceivably you could try to swap them for a stock set before your trade in, but that implies someone is willing to swap a nice set of wheels for a set with 3 years of wear on them.
Current: '15 M235i Vert
Previous: '13 335i, '08 TL-S, '00 Corvette