http://library.thinkquest.org/27066/psychology/nlcolorpsych.html

Color Psychology

   A very important aspect of our visual experience is color. The previous section on color described the color sensing mechanisms of the eye and brain. Yet the nervous impulses of the color channeldon't only go to the brain. Some pulses travel to the pituitary and pineal glands through the hypothalamus It is logical to assume that what we see, especially color, can affect the systems of the body. Psychologists and physiologists belive this to be true and are investigating exactly what each color can do to our bodies.

Red

Physiological Effect: Red has been shown to increase blood pressure and stimulate the adrenal glands. The stimulation of the adrenals glands helps us become strong and increases our stamina. Pink, a lighter shade of red, helps muscles relax.
Psychological Effect: While red has proven to be a color of vitality and ambition it has been shown to be associated with anger. Sometimes red can be useful in dispelling negative thoughts, but it can also make one irritable. Pink has the opposite effect of red. Pink induces feelings of calm, protection, warmth and nurture. This color can be used to lessen irritation and aggression as it is connected with feelings of love. Red is sometimes associated with sexuality, whereas pink is associated with unselfish love.

Orange

Physiological Effect: Orange has proven to be a stimulus of the sexual organs. Also, it can be benefitial to the digestive system and can strengthen the immune system.
Psychological Effect: Orange has shown to have only positive affects on your emotional state. This color relieves feelings of self-pity, lack of self-worth and unwillingness to forgive. Orange opens your emotions and is a terrific antidepressant.

Yellow Physiological Effect: Yellow has proven to stimulate the brain. This stimulation can make you more alert and decisive. This color makes muscles more energetic and activates the lymph system. Psychological Effect: Similarly to Orange, Yellow is a happy and uplifting color. It can also be associated with intellectual thinking: discernment, memory, clear thinking, decision-making and good judgment. Also aiding organization, understanding of different points of view. Yellow builds self-confidence and encourages optimism. However, a dull yellow can bring on feelings of fear.

Green

Physiological Effect: Green is said to be good for you heart. On a physical and emotional, green helps your heart bring you physical equilibrium and relaxation. Green relaxes our muscles and helps us breathe deeper and slower.
Psychological Effect: Green creates feelings of comfort, laziness, relaxation, calmness. It helps us balance and soothe our emotions. Some attribute this to its connection with nature and our natural feelings of affiliation with the natural world when experiencing the color green. Yet, darker and grayer greens can have the opposite effect. These olive green colors remind us of decay and death and can actually have a detrimental effect on physical and emotional health. Note that sickened cartoon characters always turned green.

Blue

Physiological Effect: In contrast to red, blue proves to lower blood pressure. Blue can be linked to the throat and thyroid gland. Blue also has a very cooling and soothing affect, often making us calmer. Deep blue stimulates the pituitary gland, which then regulates our sleep patterns. This deeper blue also has proved to help the skeletal structure in keeping bone marrow healthy.
Psychological Effect: We usually associate the color blue with the night and thus we feel relaxed and calmed. Lighter blues make us feel quite and away from the rush of the day. These colors can be useful in eliminating insomnia. Like yellow, blue inspires mental control, clarity and creativity. However, too much dark blue can be depressing.

Purple

Physiological Effect: Violet has shown to alleviate conditions such as sunburn due to its purifying and antiseptic effect. This color also suppresses hunger and balances the body's metabolism. Indigo, a lighter purple, has been used by doctors in Texas as an anesthesia in minor operations because its narcotic <"A soothing or numbing agent.">qualities
Psychological Effect: Purples have been used in the care of mental of nervous disorders because they have shown to help balance the mind and transform obsessions and fears. Indigo is often associated with the right side of the brain; stimulating intuition and imagination. Violet is associated with bringing peace and combating shock and fear. Violet has a cleansing effect with emotional disturbances. Also, this color is related to sensitivity to beauty, high ideals and stimulates creativity, spirituality and compassion. Psychic power and protection has also been associated with violet.

Brown

Psychological Effect: Brown is the color of the earth and ultimately home. This color brings feelings of stability and security. Sometimes brown can also be associated with withholding emotion and retreating from the world.

Black Psychological Effect: While comforting and protective, black is mysterious and associated with silence and sometimes death. Black is passive and can prevent us from growing and changing.

White

Psychological Effect: White is the color of ultimate purity. This color brings feelings of peace and comfort while it dispels shock and despair. White can be used to give yourself a feeling of freedom and uncluttered openness. Too much white can give feelings of separation and can be cold and isolation.

Gray Psychological Effect: Gray is the color of independence and self-reliance, although usually thought of as a negative color. It can be the color of evasion and non-commitment (since it is neither black nor white.) Gray indicates separation, lack of involvement and ultimately loneliness.