There is a long history in design of using blue colors as 'calming' and 'relaxing'. If you want someone to feel peaceful, you paint the walls blue. With the more recent studies on the impact of blue light from screen for sleeping, it seems there is a physiological response that does not match this design rule.
Is there a difference in wavelength, or is there a cutoff of exposure from when it is calming to when it becomes a response to stay awake? Or am I misunderstanding something in the two cases?
blue lights are used in many jurisdictions as part of a warning sequence - police, in particular. as they frequently flash, the brain probably interprets them in a threatening way - think sharp knives cutting. it's imagery that often is shown in movies and TV shows so most likely it's perceived consciously and unconsciously as an alarm
- Color and psychological functioning: a review of theoretical and empirical work
https://www.frontiersin.org/articles/10.3389/fpsyg.2015.00368/full
- Effects of four psychological primary colors on GSR, heart rate and respiration rate
https://thekeep.eiu.edu/cgi/viewcontent.cgi?article=4906&context=theses
- Color psychology and color therapy; a factual study of the influence of color on human life
http://www.academia.edu/download/30219472/table_of_contents_134504.pdf
- EFFECTS OF COLOUR OF LIGHT ON NONVISUAL PSYCHOLOGICAL ...
https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.sciencedirect.com/science/article/pii/S0272494400901981&ved=2ahUKEwjRjO34lO3lAhVl2aYKHdNrBW8QFjAUegQIChAB&usg=AOvVaw2yOFFWH-BtnAaA8MmBD4Tr&cshid=1573853687441
Hope these help. Also, consider contacting the authors.
Best ,
A.
Blue makes you feel safe and relaxed.
Blue evokes feelings of calmness and spirituality as well as security and trust. Seeing the color blue causes the body to create chemicals that are calming. It is no surprise that it’s the most favored of the colors. Dark blues are great for corporate designs because it helps give a professional feel, but using too much can create a cold, disengaged feeling. Light blues give a more relaxing, friendly feel. Great examples are social sites like Facebook and Twitter who use lighter blues.