I would go with medium tone gray/blue walls. You can the print off copies of album covers and frame them in black frames. Get Navy and white bedspread.
How should I redecorate my room ( what color should I paint it - etc) based off of this brief description. I enjoy a lot of rock and punkish bands ( MCR, FOB, P!ATD ) . My top fav colors are black / navy / white. I love anime , and I love posters?
I would search on the Internet for Pictures of rooms which i like and try to decorate my room after this templates.
If you love Postershang up as much as you like, Frame them and put them on the wall instead of stick it directly on the wall.
Paint the room in your favorite Color and put some accessoires in it, maybe some Anime stuff.