What you'll need:
- Commercial tile cleaner with a mild abrasive.
- Bleach or hydrogen peroxide to remove any mold.
- Repair kit for any damaged grout; repair beforehand
- 1800 grit sandpaper
- Orbital sander
- High adhesion primer for glossy surfaces
- Paint brush
- 1/8" short napped roller
- Oil, latex or epoxy based high gloss paint
- Clear urethane finish
- Vacuum/cloth for cleanup
Vacuum all remaining dust and then just use a wet absorbent cloth to wipe down/clean the surface. Let dry.
Now you'll be using an oil based high adhesion primer. Oil versus water based: oil primers tend to have better colour and stain blocking effect, giving you a more neutral base to paint ontop of. They also offer a better adhesive base for the paint that will soon sit ontop. Apply two coats and sand gently with the 1800 grit sandpaper after second coat dries, removing any noticeable rises in the overall surface. Don't sand too vigorously, just enough to create an even surface for paint to be applied upon. Remove dust and cleanup surface again with damp cloth.
You're now ready to apply the paint. There's debate between using oil or latex based paints, not to mention epoxy finishes for high traffic tiling. Many note that latex, although dries quicker, finishes with a characteristic soft, rubbery finish that is prone to rip off if scratched. So an oil based paint might be a better choice in surfaces that might have to endure some occasional mishandling. An epoxy coating can be used for areas that are regularly wet, providing a high gloss and better adherence character compared to both latex and oil based paints. Apply several thin coats of a semi-gloss or high-gloss paint, following your paint's direction for thinning the mixture. The secret to a good paint job is to err on the side of being a turtle rather than a hare: slow and steady. Apply several thin coats, with sufficient time inbetween for each coat to dry. Allow paint to dry for 2-3 days depending upon weather/humidity, and then finish with a couple of coats of clear urethane. Now you've got a yourself a repainted tile work that cost you hardly anything compared to a tile replacement job!