As far as changing the background color or perhaps using an image for a background, just go to the Environment tab in the Camera's attribute editor Here you can change the background color or use an image or texture, such as the env shader which is used to simulate a 3d sky. Good luck and have fun
Red bellows of flame have blackened my stones
Convulsing my frame and cracking my bones
Hell's dragons of steel who roar in their chains
Crawl into my caves to suck out my veins.....
-The Mountain P.F.M.