Interesting that blue light is enough! Sun drying clothes is the most effective way to get rid of annoying stains, as any Mediterranean parents would know (UV cleans even better than blue light!).

As an aside, I recently learned infants can get treated for hyperbilirubinemia using a special blue light[1].

As I was told, it was discovered when someone noticed babies with hyperbilirubinemia that lay closer to windows in the hospital ward faired better than those further away from the windows.

[1]: https://www.stanfordchildrens.org/en/topic/default?id=hyperb...