RustOleum makes a tub & tile kit. Here's a Hometalk project that might help:
Rustoleum or Homax tub and tile paint kits.
This is Linda. You can paint your ceramic tile floors, however you must do the prep work in order for it to work. You don't want it starting to peel a few weeks after you do it. So be sure to sand and clean it as described in the article below. I hope it helps you. Wishing you the best.
Thank you for your good advice.