How Do Colours Affect Us?

Different colours affect us in different ways.  

Yellow for instance is the hardest colour for the eye to take in and requires much more effort to concentrate upon it.  For this reason, things written on yellow paper are retained in the brain for far longer than that written on plain paper.

Red has the longest wavelength of any colour and for this reason grabs our attention first.  This is the reason it is the colour of stop or danger signs or stop on the traffic lights.  It can also be the colour of warmth.  Pure red has no subtlety, it can trigger excitement and aggression.

Blue has been proved in a great deal of research to be the most calming colour for the mind.  Bathrooms and swimming pools are all blue, we consider water as blue (although it's obviously clear).  People who wear blue tend to be calmer than those who don't.

Green is in the middle of the spectrum and requires no change in the eye to take it in.  For this reason, it is the most relaxing and restful of colours.