How to Add Color to Porcelain Tile

Dull the existing porcelain tile with the belt sander and medium sandpaper belt, running it in one direction over each tile, forward and back. Don’t sand the grout lines between the tiles.

Spread primer over each tiles with a paintbrush, keeping the layer thin and smooth. Brush it all in one direction. Don’t cover the grout lines.

Let the primer dry 12 hours.

Spread paint over each tile with a paintbrush, in the same way you did you the primer. Keep the brushstrokes in one direction, and keep the paint layer very thin. Don’t paint the grout lines.

Let the paint set for 12 hours.

Add a second layer of paint in the same way as the first. Let it dry. Brush on a third coat. Let it dry 24 hours.

Spread polyurethane over the tiles, again working tile by tile and keeping the layer thin and even.

Let the polyurethane set for 12 hours. Sand it lightly by hand to dull the sheen. Wipe off the dust.

Brush on a second layer of polyurethane. Let it dry 12 hours. If it needs a third layer, dull the second layer with sandpaper before applying the third layer.