Worldwide, blue is the favorite color, reports a psychologist for The Financial Times. At the "cool" end of the spectrum, blue can induce such physiological effects as lowering blood pressure, slowing breathing and releasing muscular tension.

It is one of the reasons why airline cabin crew often wear blue, to calm the nerves of passengers who don't like to fly. Blue wasn’t so popular in prehistoric times when the color signaled rotting - and therefore poisonous - meat.

Blue is associated with the sea and sky. It is also a common bedroom paint color since it is known to aid sleep. Blue is even thought to promote healing and suppress appetite. Maybe an easier way to control what you eat would be to don blue clothing, paint your kitchen sky blue, and take up fishing.