Bad Boy hip hop mogul Sean "Diddy" Combs moved his annual White Party from swank St. Tropez to "just eh" East Hampton, N.Y., but that didn't mean he was relaxing the rules -- wear all white or you'll be shown the door.

TMZ reports most of the "Making the Band"-maker 's friends -- including Mariah Carey, Busta Rhymes, Donna Karan and Ashley Olsen -- complied. But former "Top Chef" host Katie Joel, wife of piano man Billy Joel, made a fashion faux pas when she showed up in cream, not white. The horror!

Combs' party police cited Joel for a violation, and requested that she change her outfit in order to attend the fete. Joel opted to go home instead.