Properly installed bathroom tile can last for 20 years or longer, long enough for the tiles to become outdated in colour and style. If your bathroom tile is showing its age in its colouring, but not in the structure of the tiles, they are a good candidate to be painted instead of replaced. Take care when painting your tiles to only get the tile paint on the tiles. The grout can be left alone or painted with special grout paints if you desire.
Clean the bathroom tiles well. Remove any dirt, dust or soap scum that may be clinging to the tiles and dry them well. If you also plan on painting the grout, wait at least 24 hours after washing the tiles before painting the grout to ensure that it is completely dry.
Cut the paint in on the edges of the tiles using the angled paintbrush. Work in toward the centre of the tile in even strokes, taking care not to cover the grout joints with the paint being used on the tiles.
If you are painting the grout joints, wait 24 hours for the paint to dry, then carefully apply grout paint directly to the joints using an artist's paintbrush. Work in slow, careful strokes to cover all areas of the old grout. Wait an additional 24 hours for this paint to dry completely.
Seal your newly painted tiles with a urethane sealer to protect them against moisture damage. Use a paint roller to cover the tiles with a clear coat of sealer. The sealer will go on wet looking; look for dry areas by standing just to the side of the tiles and looking sideways into the light to ensure no areas are missed. Wait until the tiles are fully dry with no tacky areas before using the bathroom.
Urethane paints and sealers can contain high amounts of VOCs. Run the bathroom fan or open a window while you work to help air out the room.