Physiological Effects
Here are some more facts about the physiological effects of colours, based on scientific data collected by numerous colour therapists from all over the world.

Red
When a person is exposed to red, the pituitary, an endocrine gland, is activated. On receiving a signal from the pituitary, the adrenal gland in turn secretes adrenalin. It is this adrenalin that flows into the blood stream and triggers off the whole range of physiological activity listed below. Of course the time within which they manifest depends on the individual's level of physiological equilibrium:

• The blood pressure increases.
• The pulse rate increases as a result of higher blood flow.
• The respiratory rate picks up.
• The autonomic nervous system starts functioning and the reactions become involuntary.
• The taste buds become more responsive.
• The appetite improves.
• The sense of smell is intensified.
• Men are drawn towards yellow-based reds but females find blue-based reds more attractive.

Orange
According to The Wagner Institute for Colour Research, Santa Barbara, colours can be of two types: a classifying colour that 'holds position' and thus appeals to a few people; and a declassifying colour that alters its position in order to increase its appeal to more people. The status of orange, being a blend of red and yellow, would thus depend on its varying shades of light and dark. As a classifier, orange is of immense importance to a person who intends to make a buying decision. Orange induces the following physiological effects:

• The appestat elevates and the appetite improves.
• Induces sleep.
• The rate of blood flow decreases.
• When fused with blue, orange induces a feeling of tranquillity.

Yellow
Yellow being a declassifying colour, appeals to a large number of people and its effects on the body are as follows:

• Yellow is the most complex colour for the human brain to process but it is also the most prominent colour that we can see. The presence of yellow, more than other colours, affords us the quickest vision of an object.
• Yellow in nature, when combined with black elicits a guarded response, inherent in humans.
• Yellow evokes a brief response from a person under stress and adds to it by preparing him/ her to face it or flee from it.
• Children, who are kept in rooms painted yellow, tend to cry more often.
• Many people suffer from frequent allergic reactions when exposed to yellow surroundings.

Green
Since different shades of green arouse unfavourable reactions in many people, it is generally thought of as a classifier colour. Of course greens with more white and less yellow are found to have a wider appeal. The positive physiological effects of green are:

• It facilitates the production of blood histamine, a compound found in almost all body tissues. Histamine performs the important functions of dilating the blood vessels and contracting smooth muscles like the lungs. It is also an important mediator of inflammation.
• It reduces allergic reactions to foods and hypersensitivity to additives like monosodium glutamate.
• It halts the release of histamine from mast cells and basophils, even under stimulation from antigens. It stabilizes the mast cells and basophils.
• It is very effective in reducing the discomfort arising from ailments like eczema, diarrhoea and gastrointestinal problems.
• The presence of green stimulates the release of vision chemicals that improve the eyesight. The reverse colour of exposed body tissue (which is mostly red) is surgical green, a shade, which facilitates the doctor's vision.

Blue
Blue is the most soothing of all the colours. The presence of blue stimulates the brain to release eleven neurotransmitters, which are hormones that induce a calming effect on the body, manifest through:

• Slowing down of the pulse rate, accompanied by deep breathing.
• Reducing the levels of perspiration and a lowering of body temperature.
• An absence of the fight or flight response induced by yellow.
• Presence of blue in food would induce an abrupt termination of appetite.

Brown
The most environment friendly of all the colours, brown, inspires a sense of security. It induces a favourable atmosphere for carrying out daily activities. The positive presence of brown helps the body and the mind.

• Diminishes mental depression by reducing feelings of fatigue and irritation.
• Promotes the synthesis of serotonin, a neurotransmitter.
• Stimulates the release of prostaglandin E, a hormone-like substance, in the tissues and body fluids. This in turn plays an important role in the functioning of the womb, brain, lungs, kidney and semen.
• Increases the production of tryptophan amino acid that affects sleep, migraine headaches and immunity levels.