I've done it both on purpose and not on purpose. Fabric has two sides and I use the one I want. In the Grassy Creek Bonnie Hunter mystery, I used a heavily metallic gray print with both sides. In the bed of the quilt I used the back because I didn't want the metallic, but in the border I wanted the metallic elements to show.
Many years ago I made a Storm at Sea, I later figured I had handled each block about 27 times just in the sewing process, much less the layout and quilting of the project. I didn't notice until it was hanging in a guild quilt show that one of the large center squares was "inside out". If anyone else ever noticed, they didn't mention it to me. That was when I really felt reassured that it was ok to use either side. It wears the same, and if it looks better -- do it!