Installing blue streetlights resulted in a 9% decrease in crime in Nara, Japan. It also put an end to suicides at Keihin Railway’s Gumyoji Station after the railway installed blue lights on the ends of platforms.
“There are a number of pieces of data to prove blue has a calming effect upon people. However, it’s an unusual color for lighting, so people may just feel like avoiding standing out by committing crimes or suicide under such unusual illumination.”