Recall that I'm reading Goethe:
From these three, light shade and colour, we construct the visible world, and thus, at the same time, make painting possible, an art which has the power of producing on a flat surface a much more perfect visible world than the actual one can be.
[Johann Goethe, Theory of Colour 1810
One of the essences of Goethe's theory is that colors result from an effect of the eye. When light is separated from darkness, yellow and blue result. In his famous experiments, Goethe looked at light and dark surfaces through a prism. Here is a look at my studio through a liquid filled prism, as Goethe is likely to have used:
There is a blue fringe atop bright areas, and a yellow edge to the top of dark areas. Moving closer to the bright lines of sun light revealed more colors, still mixing to white in the center:
When a modern flint glass prism (nD = 1.65) is substituted for the water prism (nD = 1.33), the dispersion is greater and the full spectrum is obtained.
The same area imaged through the Amici compound prism (nD (eff) = 4.95) that I use for stellar spectra:
It appears that Goethe's prism experiment may have been constrained by the equipment he had available. Green, it seems is green.
The painting at the top of this article shows the view through a prism of light - color's effect on the emotional state. Although there is no green paint, an examination of the full size painting [900K] reveals greens in abundance. The opponent nature of color - it remains a metal construct, as yet undiscovered (yet!) by science - is reflected in a painting of one's own psyche, 'more perfect than the actual one is.'
![full size painting [900K]](http://homepage.mac.com/cheilman1/images/goethel.jpg){kind=link}