AbstractThe use of light as a therapeutic agent has a long history. However, there is little or no scientific foundation for much of what has been published in the area of color therapy. There is a good foundation for the treatment of neonatal jaundice with blue light. Preliminary basic research suggests that when used with photodynamic agents, malignant tumors may be treatable with white light. Other studies suggest that psoriasis can be treated with ultraviolet light when the affected area is first covered with anthracene. Evidence is accumulating that shows how the human body does interact with light at a hormonal, metabolic, and endocrine level. I conclude that there has never been a better time for competent scientists to investigate whether there are additional effective color therapeutic procedures in addition to the use of blue light for jaundice.