Abstract: An apparatus and method for deriving, with respect to a particular individual, those color hues which have particularly major impact upon the individual in terms of being most positive or most negative. The patient is subjected to a display of changing color hues and is fitted with a biofeedback assembly that measures involuntary body system responses as the individual views the display. These measurements are coordinated with the color display in order to identify each color shade's impact upon the individual. In one preferred embodiment, the color display is generated by a monochromatic light source in order to subject the patient to true or pure color.