If you look in all the home decor magazines and on Houzz, today's trend is to paint the trim white. It will give it crisp and clean feel. White does'nt fight with any other colors, even if it is buttercream. You can certainly paint thr trim a different color than white but it would need to be a color that would blend with the rest of the room. Without seeing a phot of the space, white is a good save choice.