If you use a spray paint in thin coats you won’t throw off the balance. If you want classic white/black then buy a white one and add the black, it’s easier than the other way around.
Otherwise keep colours to a minimum and key the painted surface with 400 wet paper. I like coloured primers like Army Painter for this sort of job, they have good adhesion and high opacity. You can dye some plastics with Rit dye or similar, RC car people do that with wheel rims.