Most people know that the ear system has two functions: hearing and balance. It is less well known that the visual system also has two functions. The first is seeing. The second is a set of non-visual functions including circadian rhythm. Mechanisms are being discovered that are particularly sensitive to blue light. So short-wavelength, or blue, light inhibits melatonin which is a chemical that makes you drowsy. So looking at bright lights late at night, especially blue ones, can contribute to a poor night’s sleep. So put your smart tablet away now and go to sleep!
In all seriousness though, I knew there was a reason why I do not like watching Chelsea on Match of the Day.
Studying these functional effects of colour and how they can be used in design is a major theme of the research I lead at the University of Leeds in the School of Design. If you have interest in these areas please contact me.