Having a tub and shower enclosure that don't match the rest of your bathroom can be an eyesore, and replacing them can be expensive. Fiberglass tubs and showers can seem particularly difficult to recolor, but if you have the proper instructions and supplies, the process can be easy and provide stunning results.
Sand the tub and shower with a 320-grit sand paper until the surface is dull.
Mix one part muriatic acid with five parts water in a plastic bowl. Use a nylon scouring pad to scrub the tub and shower surface with the solution.
Rinse the tub and shower completely with water and allow to dry.
Use masking tape to cover faucets, hardware and other areas you do not want painted.
Apply a layer of epoxy-based primer to the surface of the tub and shower with a spray gun or can. One coat should be sufficient. Allow to dry.
Apply an epoxy-based paint to the the entire tub and shower area with a spray gun or can. Allow to dry. If the color is not dark enough, apply a second coat.