Quote (Ninjaah @ 23 Aug 2011 18:53)
I've tried that several times, with different pictures and front other computers. It won't let me have a picture

Can you view my profile and tell me if the black/orange is blocking/in the way of putting in a background?

The d2jsp themes will not block any backgrounds (for example Black/Orange).

Make sure that the wallpapers you download do not exceed 512,000 Bytes, and that the file name ends with jpg, jpeg or png

Because of the bytes limit, you might want to find good looking wallpapers with the same pixels (often 1920 x 1080), but with a smaller size, therefor I look for Animated pictures, Art (Diablo III have good art pictures).
Often it takes a long time to find pictures, but I found this in 2 minutes by just searching for 'Diablo III art' in Images section at google
http://www.diabloiiikore.com/photos/-Diablo-III-Monster-Art/thefallen.jpg 
(Fits perfect for a black/red/orange background imo)