Just sand them a little, wash them, then put on a good primer; next, a couple coats of your fav paint.

Another related question... the entire bathroom is brown... chocolate brown floor and tub tiles, dark cabinets, brownish-granite. white, unpainted walls. should I paint the walls pink and leave the rest as brown? I am also looking for a fabulously girly mirror (maybe in white). is that too many colors?

You would need to scuffing the cabinets to give them some adhesion and then used a high adhesion primer and an oil based paint.