"What, then, is the cause of colours in nature?  None other than the disposition of bodies to reflect the rays of a certain order and to absorb all the others. It was thought that is was due to the rebounding of rays, as of a ball, on the surface of a solid body.  Not at all!  Newton taught the astonished philosophers that bodies are opaque due only to the wideness of their pores; that light is reflected in our eyes from inside these same pores; that the smaller the pores of a body are, the more transparent the body will appear...."

Voltaire, 
Les Lettres Philosophiques 

"The retina of the human eye contains three types of cells which are sensitive to three different radiations of various wavelength sectors: they are called cones. In addition there are the rods, cells that apparently perceive only differences in brightness. These cells are tiny antennas, of which there are about 15,000 on one square millimetre of retina."

Harold Keuppers, 
The Basic Law of Colour Theory 

Absolute green is the calmest colour in existence: it doesn't move, it doesn't express joy, sadness, passion; it desires nothing, asks for nothing.  This absolute absence of movement is a property beneficial to jaded people and spirits too...

Wassili Kandinsky, 
The Spirit in the Arts 

"What, then, is the cause of colours in nature?  None other than the disposition of bodies to reflect the rays of a certain order and to absorb all the others. It was thought that is was due to the rebounding of rays, as of a ball, on the surface of a solid body.  Not at all!  Newton taught the astonished philosophers that bodies are opaque due only to the wideness of their pores; that light is reflected in our eyes from inside these same pores; that the smaller the pores of a body are, the more transparent the body will appear...."

Voltaire, 
Les Lettres Philosophiques 

"The retina of the human eye contains three types of cells which are sensitive to three different radiations of various wavelength sectors: they are called cones. In addition there are the rods, cells that apparently perceive only differences in brightness. These cells are tiny antennas, of which there are about 15,000 on one square millimetre of retina."

Harold Keuppers, 
The Basic Law of Colour Theory