A little basic information, and an introduction into the theories behind colour psychology- the general subject which I have chosen to take a closer look at for my 'Book Works' brief (developments of which can be found on my Design Practice blog).
Color psychology is the study of color as a factor in human behavior. This includes very diverse studies, ranging from quantifying individual color preference to investigating the relationship between shirt color and match outcome in English football. In ways "color psychology" is a rather young direction in research, in that it is has not been strongly propagated in clinical settings.
When a yellow wall is hit by white light, be it sunlight or artificial, the wavelengths of the color yellow reflect off the wall into our eyes, stimulating our brain. Different colors emit different lengths of wavelengths of light - some shorter, some longer - when they are hit by white light; this light is energy which can stimulate different parts of the brain, particularly through the retina and skin. The general concept is not dissimilar to how sunlight produces growth in plants; different light wavelengths are essentially exercising and forcing growth and activation of different parts of the brain. A long wavelength of a bright yellow room will stimulate emotional, irrational parts of the brain, whereas a deep blue with a far shorter wavelength has a calming effect and tends to stimulate cold rationale, logic, and mathematical parts of the brain.
The color of placebo pills is reported to be a factor in their effectiveness, with "hot-colored" pills working better as stimulants and "cool-colored" pills working better as depressants. This relationship is believed to be a consequence of the patient's expectations and not a direct effect of the color itself. Consequently, these effects appear to be culture-dependent.
BLUE PUBLIC LIGHTING
In 2000, Glasgow installed blue street lighting in certain neighborhoods and subsequently reported the anecdotal finding of reduced crime in these areas. This report was picked up by several news outlets. A railroad company in Japan installed blue lighting on its stations in October 2009 in an effort to reduce the number of suicide attempts, although the effect of this technique has been questioned.
USE OF COLOR TO CREATE AMBIANCE
Color has long been used to create feelings of coziness or spaciousness. However, how people are affected by different color stimuli varies from person to person.
The hues in the blue range have been shown to have the highest preference amongst people.
There is evidence that suggests that people tend to prefer certain colors depending on the ambient temperature. People who are cold prefer warm colors like red and yellow while people who are hot prefer cool colors like blue and green.
Studies have shown that colors have an effect on people's moods and emotions. One problem that exists is that these studies are inconsistent on determining which colors bring out or reflect specific moods and emotions. In other words, the relationship between color and behavioral response exists but there hasn't been any consistency as to how it exists.
Some research has concluded that women tend to feel pleasant seeing "warm" colors while men tend to feel pleasant seeing "cool" colors.
A few studies have shown that cultural background has a strong influence on color preference. These studies have shown that people from the same region regardless of race will have the same color preferences. Also, one region may have different preferences than another region (i.e., a different country or a different area of the same country), regardless of race.
Children's preferences for colors they find to be pleasant and comforting can be changed and can vary, while adult color preference is usually non-malleable.
LIGHT, COLOR, AND SURROUNDINGS
Light and color can influence how people perceive the area around them. Different light sources affect how the colors of walls and other objects are seen. Specific hues of colors seen under natural sunlight may vary when seen under the light from an incandescent (tungsten) light-bulb: lighter colors may appear to be more orange or "brownish" and darker colors may appear even darker. Light and the color of an object can affect how one perceives its positioning. If light or shadow, or the color of the object, masks an object's true contour (outline of a figure) it can appear to be shaped differently than it really is. Objects under a uniform light-source will promote better impression of three-dimensional shape. Although more evidence is needed, it is believed that the color of objects can affect how one perceives their motion. Under a uniform light source objects of different color can more easily be seen moving in different directions. However, under variable light sources, which are more often encountered, the motion of objects can be masked or not perceived as easily because one's mind is preoccupied with trying to differentiate the contour and color of the objects.
COLOR IN JUNGIAN PSYCHOLOGY
Carl Jung is most prominently associated with the pioneering stages of color psychology; he was the first to delve into the topic and turn it into a field of inquiry in its own right. Jung was most interested in colors’ properties and meanings, as well as in art’s potential as a tool for psychotherapy. His studies in and writings on color symbolism cover a broad range of topics, from mandalas to the works of Picasso to the near-universal sovereignty of the color gold, the lattermost of which, according to Charles A. Riley II, “expresses … the apex of spirituality, and intuition”. In pursuing his studies of color usage and effects across cultures and time periods, as well as in examining his patients’ self-created mandalas, Jung attempted to unlock and develop a language, or code, the ciphers of which would be colors. He looked to alchemy to further his understanding of the secret language of color, finding the key to his research in alchemical transmutation. His work has historically informed the modern field of color psychology, which is currently studied most intensively for marketing purposes, on the one hand, and by academic scholars on the other. Color psychology and color symbolism have been expounded upon by intellectuals and academics from different fields of specialization, as can be noted in papers published for an Eranos conference on color symbolism.
Inherent difficulties in properly controlling trials of color's effect on human beings mean that a subject's expectations and cultural bias cannot be ruled out. Moreover, much evidence is anecdotal (e.g. the blue street lighting case) or based on data that includes confounders (e.g. the shirt-color correlation). Chromotherapy, a form of alternative medicine, is based on the hypothesis that distinct colors have health effects unrelated to the aforementioned placebo effect. Such profound claims are the subject of skepticism and are often regarded aspseudoscience.