Cool colors visually recede, while warm colors advance. To the eye, when a wall appears to recede, it looks farther away, therefore, the room looks larger. Cool colors reflect light, while warm colors absorb it. Use these tricks by applying cool colors to the walls to bounce light around, such as blues, greens or cool whites. Avoid warm colors such as red, orange or yellow to make the walls appear farther away and the room larger.
Lighter, less-saturated colors reflect natural light, and the more light that bounces around the room, the brighter and bigger it seems. If you choose a dark color such as deep browns or dark reds, the light is absorbed by the paint colors, making the walls appear to recede.
Don't neglect the ceilings when you're considering paint color. Lighter paint colors make the ceiling brighter and seem farther away and higher, while darker colors make the ceiling feel closer and may feel slightly claustrophobic. Choose whites, creams, or light, airy blues for your ceiling to help the room appear bigger.
Consider the sheen of the paint you choose. Most interior paints are available in a variety of sheens, from flat to high-gloss. High-gloss paints helps light bounce around the room, while flat paint makes the walls appear less bright. However, flat paint disguises flaws in the walls, so if your room has imperfect walls, choose a flatter sheen. Many bedrooms are painted in an eggshell finish, so if the walls are in relatively good condition, choose either an eggshell or satin finish.