The colour blue seems to have every type of emotion connected to it...it can be calming yet evocative of sadness.

In Iran it's the colour of  mourning whereas in the West wearing something blue is a bridal tradition used to represent love.

In France during the 19th Century blue became fashionable to wear among artists and the general public.  Not that this was the influence on Picasso's Blue Period, during which he demonstrated his own melancholy through a series of sentimental and sombre paintings.

Madame Soler

Suzanne Bloch

I didn't intend to look too deeply into the background of a colour but it's actually quite interesting!  And on a lighter note, it definitely has the best shade names...

Azure, Cerulean, Cornflower, Cobalt, Prussian

I'm partial to a bit of Yves Klein Blue, or IKB as it's officially known (although it doesn't quite have the same ring to it does it?)