The ceiling is often overlooked when you're redecorating, but in reality, it is the ultimate canvas for a painted sky scene -- it's overhead, as it should be, ready to view while reclining or relaxing. The colors you need depend on whether you'd like a bright daytime sky, a look reminiscent of dawn or sunset, or even a full-on night view. A sky-blue color is the base shade for anything involving daytime, while indigo suits a night sky.
Blue Sky Basics
Prepare for painting a blue sky by first moving everything out of the room, or away from the area where you're working. Cover the entire floor with a drop-cloth. Remove dust and cobwebs from the ceiling with a duster.
Cover areas that you don't plan to paint, such as a light fixture or the edges of the walls along the ceiling, with painter's tape and newspaper to protect them. Climb a ladder to do so, if necessary.
Pour the primer into a paint tray and coat the entire ceiling, using a roller for the large expanses and a brush for the perimeter and areas the roller doesn't reach. Allow primer to dry completely.
Pour the light blue latex paint into a paint tray. Paint the entire ceiling using a roller for the expanses and a brush for the difficult-to-reach areas. Allow paint to dry completely, applying a second coat, if necessary.
Pour a bit of white latex paint into a paper plate. Pour a small amount of black next to it, and another pool with a small amount of the sky blue. Dip a paintbrush into the white, painting a basic cloud shape in a desired location on the ceiling. Dip the brush again in white, picking up bits of black to create gray, or a little blue to create shading on dark areas of the cloud.
From Sunrise to Sunset
Create a sunrise or sunset effect by making the ceiling sky lighter on one side, darker on the other, with color mixed in. Paint the ceiling a basic sky blue, mixing in a little white to create the lighter color, which would be near the sun in the sky. Mix a little indigo into the paint for the area opposite the sun.
Paint a few clouds or cloud streaks near the area where the ceiling sun is rising or setting, using white or mixes of white, blue and black to create color variations.
Pour a little red and yellow latex paint into separate pools on a paper plate. Pour some latex glaze near them. Mix the glaze into both colors; then load both onto parts of a paintbrush, painting streaks in the sky or within the clouds near the lighter end of the ceiling sky. The glaze gives the streaks a more translucent look and can be used to create sunbeams.
Starry, Starry Night
Create a night sky by painting the entire ceiling indigo after the primer dries. Allow paint to dry completely.
Add stars by dipping the bristles of a stiff paintbrush into a shade such as white, yellow or light blue, or a little of each. Flick the bristles with your thumb as you flick your wrist toward the ceiling to unload the paint onto the ceiling. Continue the process over the entire ceiling, adding more stars in one "band" to create a Milky Way-effect spanning the ceiling. Load a toothbrush with paint and flick the bristles with your thumbnail as you flick your wrist to create fine areas of stars.
Load a toothbrush with glow-in-the-dark paint and flick it in various areas around the ceiling so some stars are visible when lights are off. Paint larger elements such as comets, if desired, for added effect.