The art of color science is fascinating. Many people have positive, calming and re-focusing reactions to the color blue in various environments via paint, lighting, etc. However, at night it has a different impact. According to Harvard Health – “blue wavelengths—which are beneficial during daylight hours because they boost attention, reaction times, and mood—seem to be the most disruptive at night.”
During the day we need light and at night we need darkness to keep our biological timekeeper in sync with our need to work and play during the day and to sleep at night (circadian rhythm). Light, any type of light, decreases the release of melatonin, the hormone that promotes sleep.
Exposure to natural light (and even artificial light) during the day actually promotes good sleep. Melatonin levels will stay low during the day and then the body will start to secrete more melatonin once it becomes dark. Any light at night will alter the circadian rhythm and negatively impacts sleep. Harvard’s study found that blue light is the most disruptive for sleep. They recommend using dim red light, at night when needed, because it was found to be the least disruptive to our biological timekeeper. For the purposes of improving sleep, they also recommend spending as much time as possible, in bright light during the day and refraining from bright screens 2-3 hours before bedtime.