Create an accent wall behind the bed. Paint this wall a lighter shade of blue, such as cornflower blue or Tiffany blue. Or you can cover it in wallpaper that incorporates blue and white or blue and cream in a dynamic pattern.
Choose bedding, linens and throw pillows that incorporate the dark blue of the walls in a pattern with white or cream. For example, dark blue flowers or pinstripes against a light background will help make the room seem more cheerful.
Install white or cream window treatments on the wall. Choose fabric treatments such as roman or balloon shades or standard curtains to soften the dark blue of the surrounding walls.
Hang a large mirror on a wall that is opposite a window. The mirror should have a light-colored frame. This will instantly enhance the amount of light and space in the room.
Select white or cream-colored furniture for a dresser, headboard, nightstands or an armchair. Darker colored pieces would blend into the walls, adding to a dreary effect.