There are studies in Japan that showed train stations with blue lights installed have lower instances of attempted suicides than stations without blue lights [1]. There are also studies that indicate time in nature is associated with lower stress levels and blood pressure, regardless of income [2].

[1] https://www.bbc.com/future/article/20190122-can-blue-lights-... [2] https://www.sciencedaily.com/releases/2024/02/240207120426.h...