Leonardo da Vinci identified. It rarely happens that the shadow areas of objects are really similar in color to the illuminated pot. The various surfaces of objects partake of as many views as I reflected from surrounding objects. The first of all simple colors is white, although philosophers will not acknowledge that either white or black to be colors. But as painters cannot do without either, we shall place them among the others. And according to this order of things, what will be the first yellow the second, green, third, blue, the fourth, red, the fifth, and black the seats we shall set down white for the representative loss, without which no color can be seen.

Yellow for the earth, green for water, and blue for air, red for fire, and black for total darkness. Leonardo observed that yellow and blue form green, but it was not until another century had passed that the first systematic attempt was made to organize color.