Generally, no. If you are doing a 4" or full backsplash, most people choose to carry the same stone from the countertop to the backsplash. If you have an island in your kitchen, some people use a different, contrasting stone for that piece.

I have never seen that done using the 4" splash. Personally I am not a big fan of using the 4" granite for a back splash especially if you plan to put tile on as well. It you are planning to use the granite as a full back splash then you could probably use a different color. Maybe you should clarify - are we talking about a 4" splash or are we talking about a full granite back splash?