Our « blue planet » is called as because seen from space, its dominant color is the blue of the seas and oceans that cover three-fourths of its surface. The blue is the color of the sea. It is also the color of the sky. The sea is a symbol of freedom: freedom of the great outdoors, freedom of this endless blue where the gaze is lost on the horizon, where these two immensities meet without that we never can achieve it. This color is often associated with peace, quiet and serenity.
Blue is a primary color, meaning that it cannot be obtained by mixing other colors. In addition, it is difficult to manufacture, to master, and blue pigments are rare in nature. Thus, in the history of colors, it is only from the twelfth century that it began to be more present in the social life, religious, artistic or symbolic.