I think that painting one wall an accent color would make your room look chopped-up and small.

My daughter just renovated a home and she wanted a feature wall behind the bed. Her bedroom is slightly wider than yours. She also has a window behind the bed. She used horizontal shiplap, painted white. Again, its behind the bed, only. She hung curtains higher and wider around the window (so that the outside of the curtains is almost as wide as her headboard. The shiplap makes the room look wider than it is, and the curtains make her 8' ceilings even taller.

And look at this cute idea for disguising your window.

Hiding off center window over bed

Some ideas