Color Hurts. The Effect of Color on Pain Perception.

Background Research suggests that colors may have an effect on human behavior, cognition, and emotions; however, little is known about their influence on pain perception. The aim of these two studies was to investigate whether colors have an impact on pain perception and to find the mechanism that underlies the influence of colors on pain. Methods In both studies, participants received electrocutaneous pain stimuli of the same intensity preceded by one of six colors (red, green, orange, blue, pink, or yellow) or a blank slide, which served as a control condition. In the first study, the intensity of experienced pain was measured; in the second study, both experienced and expected pain was measured. Results The studies revealed that colors increased the intensity of experienced pain in comparison with the noncolor condition (blank slide), regardless of both the sex of participants and whether they noticed a relationship between colors and pain intensity. Particularly, participants rated pain stimuli preceded by red as being more painful compared with pain stimuli preceded by other colors, especially green and blue. Conclusions It is concluded that colors have an impact on pain perception. Our results have important implications for the color lights paradigm applied in studies on placebo effects.