FRP (fiberglass reinforced panels) made by Masonite comes in several different textures & colors although they are all neutral-tones of grey, beige & white. In addition to bathrooms, it's also used in commercial kitchens, hospitals & industrial applications, usually as a more cost effective solution to ceramic tile in sanitary situations.
Here's a link to the Masonite website
. There should be a local distributor in your area (other than the "box" stores mentioned) that can order the panels in colors/textures other than white-pebble.