baking soda and lots of elbow grease...
It depends on the kind of spray paint used. Most brands can be removed with some thinner. There are different kinds of thinner so you may need to try several before you find the one that will work with whatever is on your tiles. You can sometimes buy a combination thinner that contains various solvents just to be sure it will work. Usually acetone thinner or lacquer thinner will do the trick.
Discover Spray Paint Art Secrets!
Hi Geneieve, Use a paint remover spray that is safe for tiles. You may want to look on the back of the gold spray paint can to see what is recommended. Or you could call Home Depot ask for the paint department and they can help you. Or here is a formula below I found on ehow. =) How to Remove Spray Paint From Floor Tile Things You'll Need Denatured alcohol Paper towel or cotton ball Soft cloth Instructions Denatured Alcohol 1. Dampen a paper towel or cotton ball with denatured alcohol. 2. Dab the dampened paper towel or cotton ball on the paint. Do not rub, as this can cause the paint to spread. Continue dabbing until the paint has lifted. 3. Spray an all-purpose cleaner or tile cleaner over the area. Wipe the cleaner from the tile with a dampened cloth to remove all alcohol residue.