wall decal tree

Alright, so this summer I plan on completely revamping my room. It's a pretty decent sized room, and I already have a theme in mind. I just need some wall color ideas.

My theme is pretty much tree branches. I plan on using lots of black frames with cool prints or pieces of my artwork in them above my headboard. I'm buying tree branch wall decals that are black, and most of the furniture in my room will be black to follow the theme.

I want to find a color that would make the room look elegant but cool and would compliment the black furniture and theme basically. I do like purple, but I'm open to any ideas.

Help please :]?