Physiological human responses to color as evidenced by the electroencephalogram, galvanic skin response, blood pressure, heart rate, respiration rate, eyeblink frequency, and oxiometry are reviewed. A casual reading of the descriptive literature on the human response to color leads one to the conclusion that color can have rather specific physiological effects. It is concluded from this review that there are reliably recordable physiological responses to color in addition to those generally associated with vision. However, it may be that some are indirect effects mediated by cognitive responses to color.