[Principles of order in the color systems of the 17th century. (Franciscus Aguilonius--Athanasius Kircher--Isaac Newton)].

Since Aristotle there have been two colour order systems: The first is according to the subjective luminosity of colours, and the second is that which is found in the rainbow. Almost all the medieval concepts of colour order were based on the subjective luminosity of colours. At the beginning of the 17th century Franciscus Aguilonius still described the traditional sequence according to subjective luminosity: white, yellow, red, blue and black in his colour order system. - Athanasius Kircher demonstrated two sequences: The first was the same as Aguilonius 's, completed by lists of symbolic qualities attributed to the respective colours; The second was the sequence of the prismatic spectrum; red, orange, yellow, green and blue. Violet was still missing from his spectrum. For that reason the idea of arranging the colours in a closed circle did not occur to him. - Isaac Newton added violet to the prismatic spectrum. Hence he was able to bring the ends of the spectrum together, forming a colour circle. He completed the colours of his spectrum "with those purple hues which, although not present in the spectrum, were familiar to painters and dyers , and in this way closed up the colour-circle into a band returning on itself" (W. Ostwald). Thus he combined the perceptual concept of the colour wheel, containing pairs of complementary colours, with the physical concept of the prismatic spectrum.