zlacker

>>ivank+(OP)
A recent Cochrane review found very little high quality evidence in either direction:

It's not clear to me why light therapy is considered as a well-researched treatment.

>>sambe+Ad1
Add to that The Influence of Color on Physiological Response, by S. Freiders, S. Lee, D. Statz, and T. Kim:

“According to our analysis, the change in neural activity and heart rate between colored flowers and the grey-scaled flowers was insignificant.”