I think a dark colour (too much of any rich but beautiful colour) really kills a room. So I vote for having the majority of walls in the safe-but-boring cream because light is a good good thing and painting one wall (and any door/window/arches) in the really dark blue.

This way I think the room is still airy and light but it's not boring and the deep blue wall is truly showcased.

I don't think red is a particularly good colour for a bedroom no matter how gorgeous - red is too energetic, too violent, and too lurid. Blue however, fab for reflection and deep sleep.