It is possible to paint over polished brass using spray paint. Since the brass cannot be scored or scratched to create an adhesive surface for the paint, use metal primer to get a more even, streak-free paint job.
Painting polished brass takes multiple coats. Allow the brass to dry completely between each coat so that the pain does not blister or wrinkle. Store the item in a sheltered place between coats to prevent dust or small insects from settling on the paint and giving it a rough surface. Wipe the item with a tack cloth between coats to ensure that the surface is clean.