You can paint over the tiles if they're in good shape. I did this in 2 bathrooms in my house. In one, I used an 2-part epoxy paint with a roller, it was a very sticky and stinky job! But it looks good and is holding up well, 5 years now. I used the stuff that is intended for bathtubs and appliances, color white. In the other room I used epoxy paint from a spray can, and that worked well too and was easier to apply. I can provide more details if you want.