You can paint kitchen wall tiles as long as you dedicate yourself to proper preparation. Wall tiles are not suited for adhesion. Prepare the tiles in the appropriate fashion, or the finish will fail. Apply a specific type of paint, or you may end up with stains.
If you apply paint directly over underprepared kitchen tile, flaking will eventually result. Your wall tile will not accept a painted finish unless you abrade it, first. Scour the tile with a low, 180-grit sandpaper. Don't stop sanding until the tile has a slight grit.
Once the tile is abraded, it will accept a primer base coat. Coat the tile with latex primer, using a roller. You can use a paintbrush to smooth the wet primer, effectively eliminating roller marks. Be sure to use a polyester paintbrush, as nylon brushes will leave brushstrokes in the finish.
Ordinary satin latex paint is fine for living room and bedroom walls. It is not always appropriate for kitchen walls, which are prone to stains. Gloss latex paint is formulated for easy cleaning. Use this type of paint if your kitchen walls are subject to stains and duress.