We all use colors to describe certain moods, thoughts, and even weather conditions. “Feeling blue,” “green with envy,” and “cowardly yellow” are commonly used phrases in our English language. But where do these sayings come from? Some of the earliest writings we have about color come from the ancient Greek philosopher Aristotle. Aristotle wrote an entire treatise about color, aptly named, On Color.1 He is credited with creating the first known color wheel, attributing four main colors to four main domains: earth, wind, fire, and water.1
Chromotherapy is defined as “the use of light of specific colors to treat health problems.”2 There are many reports in the literature about the possible benefits of color therapy. The basis for most of the studies and theories is the understanding that light (and colors) are composed of electromagnetic energy. Each color represents a different intensity, or pulse, of energy.3 The body comprises varying energy fields called chakras, depending on the system and body part. Chromotherapy assumes that illness is caused by or causes an imbalance in these chakras. True chromotherapy is intended to rebalance using specific colors, thus healing the ailment.4
Much more recent than Aristotle, the modern equivalent of the founder of color therapy could easily be Max Luscher.5 Luscher developed “Luscher’s Color Test,” which is a psychological test using the premise that sensory perception of color, as well as internal reactions to color, are combinations of not only objective preference but subconscious as well. Luscher’s test, however, has been largely criticized by much of the psychology world after a comparison study against the well-established Minnesota Mental Personality Index when it failed to correspond to established benchmarks of accuracy.6
In one randomized clinical trial, researchers explored the effect of color therapy on people who had a stroke more than 6 months previously.7 The study enrolled both the patient and the closest caregiver to show the impact of color therapy on perceived quality of life, or in this instance, purpose in life, as measured by a standardized questionnaire.7 Participants were split into 2 groups. The treatment group received 2 hours/week of color-based therapy for 16 weeks, and the control group received routine therapy. The questionnaire was administered before the study began and at the end of the trial. Results showed an average 50% improvement in purpose in life for patients in the treatment group and more than 25% improvement in purpose in life for caregivers in the treatment group.
In another small study, 64 college students were randomly exposed to scenarios suggesting anxiety, calm, or neutrality.8 Participants were then instructed to use their choice of colors to complete a standardized pre-drawn mandala, similar to a color wheel. The results were evaluated for use of colors considered warm (anxious) and cool (calm) and found no statistical difference in the choice of colors used by the participants.8
Our body perceives light rays through the retina of the eye.9 The subsequent chain of events involves complex mechanisms of the autonomic nervous system. In a study to evaluate chromotherapy in healthy people, more than 110 participants were randomly assigned to 1 of 3 groups: those exposed to specific colors, those exposed to specific modulations in light frequency, and a placebo group of those exposed to non-modulated white light. Measurements of autonomic function (heart rate, heart rate variability, skin conductance) were noted before and after the study. Results revealed significant changes in these measures in the treatment groups compared with the placebo group.10
Another uncontrolled study from 2000, viewed by some as purely anecdotal, showed that in Glasgow, where blue light street lamps were installed in several neighborhoods, the crime rate had decreased significantly after several months.11