Pick your mood

Why is the ceiling blue? It sounds like a child's query. But the reason something man-made is a certain color is based on tradition, superstition, feng shui beliefs or scientists' findings. We react differently to, say, a flamingo pink fridge than a brushed-steel one.

Color, we long ago discovered, is more than mere cosmetics. The Color Assn. of the United States has been advising home furnishing, appliance and paint manufacturers on color psychology for half a century. That's the reason home vacuum cleaners are light blue or green. Those colors make us think a 20-pound sucking machine is lightweight and easy to move around the carpet. But vacuums intended for heavy-duty garage cleanup are sold in bold yellow and red, which imply strength. White on detergent packaging signals purity while white on soda cans implies low calories.

Betty Merken, a Seattle-based artist and architectural color consultant, conducts seminars on color theory through UCLA Extension. The theory is that color, which is visible light, has an effect on health and behavior.

Blue is often used in bedrooms because it lowers blood pressure. It makes you so focused and calm, you lose track of time. To boost the energy level, add warm orange accents. Orange is on the opposite side of the color spectrum of blue, and when opposites attract, the feel of the room vibrates.

Red is good for candlelit living and dining rooms because it can increase the sense of romance, stimulate appetite and make you more conscious of time. To balance the room, use a softer intensity of red's complement, green.

Yellow in the kitchen speeds the metabolism and encourages socializing. It makes adults mentally alert but calms children. It is used in warning signs because it's the brightest color and makes objects appear larger.

Green, which signals nature and renewal, reduces nervous and muscular tensions, and refreshes tired eyes. It is used in operating rooms to counter the color red. It's often seen in libraries because concentration is easiest in a green, gray or blue environment.

White, the most popular paint color in the U.S., is good for bathrooms because it makes small rooms look larger. But in large spaces such as offices, light-reflecting white walls can cause eyestrain, headaches and tension.

Black, like white, is considered a neutral color. It can appear to advance or recede, depending on its surroundings. Feng shui followers say black increases performance. But others find it depressing if used other than as an accent color.

Pink is used in prisons and facilities that house mental patients because it reduces hostility and aggression. Some football coaches, seeking an edge, have painted the opposing team's locker room pink.

Bright orange can make people fidgety, but when mellowed with white to create peach or salmon, it's visually and emotionally pleasing.