If you would like to alter the appearance of your worn or mismatched bathroom shower tile, you can accomplish your goal by applying the appropriate type of paint. Because shower tile is ill-suited for adhesion, you must treat the surface prior to application, or the finish will fail. In addition, because shower tile is exposed to heavy moisture and duress, you must coat it with a particular type of paint that will provide durability over a long period of time.
Scrub soap scum from the bathroom shower tile, using a coarse brush. Use a heavy-duty trisodium phosphate cleanser. Dry the tile with towels.
Stimulate adhesion by scouring the clean bathroom shower tile with sandpaper. Sand the tile until it feels slightly gritty.
Apply painter's tape to the portions of the shower tile you do not want painted.
Apply an acrylic latex primer to the sanded bathroom shower tile, using a roller equipped with a nap cover. Smooth the wet primer, using a paintbrush. Wait four hours for the primed tile to dry.
Wash all painting instruments with water.
Apply appliance epoxy paint to the primed shower tile, using a roller equipped with a shed-resistant roller cover. Smooth the wet epoxy just as you did the primer. Do not use the shower for a full day.
Don't prime over unsanded bathroom shower tile, or the primer will peel. Don't paint over bare shower tile, or the finish will fail. Don't use a plain acrylic latex or oil-based paint on shower tile, or the paint will eventually shed.