Hello, I have personally not done this exciting refurb project —but here’s a few links that might be helpful.
They make paint especially for painting tile. Ask at the paint store counter.
I painted my tile a couple years ago and posted it on Home Talk. It is still holding up fabulous!! Check out my post here: https://www.hometalk.com/30107044/i-painted-and-stenciled-my-ceramic-tile