I find it odd that in W's day, when the idea of a spectrum is well known, that his approach to color is a logic of psychological impressions that steadfastly ignores what is known about the properties of light. Indeed, when W talks about color, he does not mean light but what we perceive as a quality either of substances, like snow, or surfaces, like a table top-- that is, what we refer to as the "color" of something. In this respect he notes that "black" and "white" are treated by language as colors, even though they have properties that other colors like "red," "blue," and "green" cannot have. White lightens, and black muddies, yet both are opaque-- and I do agree with W that this is curious and profound in a way that is hard to describe, and that we, as casual color namers, do not even seem to care about.
W. talks about colors "seen through a tinted glass" and not "how light is changed passing through a glass." He is obsessed with asking if there can be a "transparent white glass," and why not if there can be tinted glasses of other colors? Of interest is his discussion of surface textures that complicate color naming, color assumptions we make viewing black/white photographs, and luminosity whether implied in a painting, or supplied by a source of light through a colored medium. Still, W is more about questions than answers, and his effort is to show the "uncertainty" of our color knowledge. He uses examples of the color-blind, or just blind, to express problems in knowing how much color knowledge can be shared among different individuals. The bottom line is: very little.
Again, W discusses lightness and darkness of colors as though they were properties of "color" and not of "light." This is a rather subtle discrimination to get your mind around, but I think it reveals that colors of physical substance are merely analogous to pure color, or even the "platonic idea" of colors. A white surface will still appear white to us at varying amounts of illumination, and may still seem white even when we know we are seeing it through a tinted glass.
"72. One thing was irrefutably clear to Goethe-- no lightness can come out of darkness--... And that is something that experiments with the spectrum neither confirm nor refute."
"238. Why is green drowned in the black, while white is not?"
And a third:
Perhaps Bruno helped inspire Goethe to embark on his color quest? This quote is from the link provided by crowleycrow today, the words of that divine and denounced mystic that I have come to revere as possibly the most brilliant and sane man who ever lived.
The order and power of light and darkness are not equal. For light is diffused and penetrates to deepest darkness, but darkness does not reach to the purest regions of light. Thus light comprehends darkness, overcomes and conquers it, throughout infinity...