Northern exposure: North facing rooms don't receive very good natural light and tend to read cool and dark. But you can help compensate to make it feel brighter by choosing warmer colors. An egg-shell or satin finish will also help, since they reflect more light than flat paint does.

Southern exposure: South facing rooms receive strong light, and sometimes the space can actually feel too warm. Mellow out rooms with this exposure by using cooler colors and a flat finish.

Eastern/Western exposure: Paint color doesn't have to work as hard to counteract light issues when a room faces east or west. Neutrals tend to work well in rooms with this exposure.

There are warm and cool shades of all the colors. Each color has a wide variety of shades, so a green could be very cool (such as mint) or very warm (such as olive). Just because a room faces north doesn't mean it has to be red or yellow. If you were going to paint it green, you would simply want to choose one that is on the warmer side.