When I've done this sort of treatment for a kitchen, we hired a local glass company called Glassworks - they do everything from shower doors to lots of other decorative glass products. They have different options, but frequently an epoxy paint is on the back - it can be a variety of colors, but the blue-green tint of glass will always affect the overall color. The link below shows - we did a white painted back which is still slightly greenish-blue but not as dark as the one above. The glass measured and custom made to fit the wall - not sure what adhesive they used. We tempered the piece behind the stove just in case.
http://www.houzz.com/photos/56721/kitchenlab-modern-kitchen-chicago

If you google plate glass backsplash there is information on a company in FL that sells a paint (I think it's called glasscote but I could be wrong) if you want to paint the back yourself. Then you can get the pieces cut by a local glass shop (don't forget outlets!). According to what I've read it can be put up with construction adhesive once the back is painted. Good luck!