We caught a viewer in the hardware store who asked if they could paint ceramic tiles.
Yes, now it is possible.
First take the gloss off of the tiles with sandpaper. This is not easy to do and is best done with a belt sander. The paint companies will tell you that it is not necessary, but the reality is that by giving the paint a "toothing" into the tile will make the paint significantly stronger.
Second give the tiles a through cleaning with TSP.
Third make sure that you purchase a special "super adherent primer", like the SICO Polyprep 3 that we used. It needs to say right on the can that it is for painting over tiles. Remember that this paint sticks like crazy, but is not a good wear surface. You must paint over it with a final layer of paint of scrubble paint.
Remember that paint does not provide a wear surface like glazed tiles. You should keep some paint on hand for touch-ups later and avoid painting horizontal tiles that will be walked or worked on.