Some remarkable research coming out of Harvard and McGill with regards to light therapy. Very briefly, researchers have shown the potential for green light to reduce headache symptoms (while showing that blue light worsens symptoms) (Harvard), and for yellow light to reduce chronic pain (McGill). This news comes at a time of burgeoning use of LLLT (low-level laser therapy) for musculoskeletal injuries/pain, a technology that uses red light (and infrared light) to speed musculoskeletal healing.
Links to articles re. this research: