Goethe’s observations with a prism showed him that light did not split into seven continuous rainbow hues but that the beam had a red edge, turning to yellow, which became white in the middle until it passed into green shades that darkened to blue along its other edge.
Newton’s colour wheel contained the seven colours of the rainbow that he observed.
The 6-Color wheel proposed by Goethe, colours were diametrically opposed to each other,
as they “reciprocally evoke each other in the eye.”
Thus, yellow demands violet; orange, blue; red, green; and vice versa: thus… all intermediate gradations reciprocally evoke each other; the simpler colour demanding the compound, and vice versa.” ~Goethe, Theory of Colours, 1810 —Love this wheel!
This opened the way to symmetric color wheels with harmonious and complementary relationships.
They tend to come out a colour called ‘Pants left in wash’ ~Eddie Izzard