As is the room has, brown, tan, gray, and black. Are you willing to do more than paint the walls? Replace the black mirror for something less stark ( or just repaint it), towel bar, and hooks. Can the paneling be removed? If not I suggest you repaint it same colour as the walls. Find a shower curtain with touches of brown and tan. Pull out another colour and repaint the walls plus paneling. Find a rug saturated with colour. *I* would replace the heavy looking brown counter but don't know if that's in your budget.