I'm trying to apply a background image to Nautilus using one of the Ambiance themes (Ambiance Dark Red to be precise) in Ubuntu 14.04.
I followed this post that indicates how to change the background color and this other that says how to change the background image in an earlier version of Ubuntu.
I was able to successfully change the color but when I want to change the image a rather odd behavior occurs: the sidebar changes instead of the main part of the window: