I do not recommend painting tile as it will not hold up as well as the original tiles finish. Especially if you need to clean the area with abrasive cleaners. However if you are going to paint the tile and don’t mind getting into a regular schedule of maintenance. You can paint the tile.First rough up the tile with fine sandpaper or do it chemically. Products are available at the major home centers and may be called deglossers. Then wash the tile real well. You should use an epoxy primer as your first coat. You can find a good brand at most automotive parts supply houses or big box improvement centers. Then paint with the color and finish of your choice.