Anyone have success painting tile?

[Derriel Cribbs]

We just picked up a new flip home, built in 1960. Everything is going well in this one, but I want to do something in the bathrooms, but feel somewhat limited. Home was built in 1960, but is in great shape. Bathrooms need serious love though. Walls are tiled halfway up with tile, and floor is done in that old-school mosaic 1" tile. From experience I know that tile is in a thick grout bed. I would really like to do these bathrooms (one is coral and turquoise, and the other is pink and grey) without tearing out the tile on the walls and floor. The floor is less of an issue, can cover that as it sits. However, I have heard differing opinions on painting tile on the wall. Anyone have any experience doing it successfully? I have heard from a couple sources that a TSP bath, paint the grout, then a primer on the tile topped with an oil based paint is the ticket. However, before diving into it, I wanted to see what others have had success (or failures) with.

Please advise, would like to get this right and avoid the headache of ripping it out. 

Oil? Latex? Acrylic?

Tile is ceramic, for what that is worth. Paint would be something neutral, if not white altogether.

Much thanks, you guys are awesome.