Paint the bedroom walls a deep midnight blue color to set the stage for the celestial theme. Choose a paint featuring a soft yellow hue, reminiscent of a glowing star or moon, if you prefer a lighter look.
Enhance dark blue walls with removable glow-in-the-dark sun, moon and star-shaped wall decals. Hang a blue wallpaper border featuring glow-in-the-dark sun, moon and star designs on a yellow wall.
Decorate open wall space with outer space-themed decor. Hang a large poster detailing the solar system above the child's work desk or bed. Have the child make his own celestial wall decor by drawing sun, moon and star patterns on poster board using glow-in-the-dark markers. Install wooden sun, moon and star-shaped wall hooks for organizing clothes, robes and backpacks.
Choose celestial-themed textiles. Place yellow star or moon-shaped rugs on hardwood or tile floors. Prepare the child for sleep by enhancing his bed with a dark blue comforter featuring yellow and white moon and star designs.
Add the finishing decor touches with glowing light fixtures. Enhance a desk or night table lamp with a dark blue shade featuring white stars; the light will shine through the designs. Suspend a bright yellow light fixture resembling the sun from the center of the bedroom.