I’m surprised the section towards them end about alternating high contrast colors producing impossible colors doesn’t link to “fechner colors” [0]. I am red-green colorblind, but when I was young I would stare at my dark ceiling fan spinning over the white ceiling and see very vivid greens and purples swimming across the blades.<p>[0]: <a href="https://en.m.wikipedia.org/wiki/Fechner_color" rel="nofollow">https://en.m.wikipedia.org/wiki/Fechner_color</a>
When adjusting paint colors if what you have is too red “or on the red side” you can correct it by adding green. If what you have is on the blue side add yellow then kind of straighten out the undesirable green by adding a smidge of red. This is the sort of thing a skilled shader technician would do to match automotive or sign paint. I did this for a while for PPG<p>You might find playing with the LAB color scale in photoshop an interesting toy to see why a reddish green color has no sense. by adding red to green you end up on the gray side. basically the colors just neutralize each other.
I have always wondered why there is a transition between violet and red, if they are on opposite ends of the frequency spectrum. Despite that, they don't act like two extremes, just two positions on a "wheel". Why is color so wheel-like when the physics is just linear? What are we "seeing" when we see a violet-red? Why do we feel like violet is between blue & red?
Playing off the "chimerical color" examples - it's possible to approximate the effect of "imaginary colors" (activation of only one cone cell type) by fatiguing the other two and then looking at the target color. e.g. staring for a while at #FF00FF and then switching immediately to a #00FF00 makes the green "pop" in a strange way.
I get intensely vivid 'stygian blue' hypnagogic hallucinations right before I fall asleep. It's an intensely dark/bright blue. Very hard to describe. It usually manifests as a blob of color that pulses from the outer-edges inwards.<p>Humorously, Negativland, the amazing decades old plunderphonics group, had a whole prank site[1] and a Over the Edge[2] radio show[3] regarding the 'fourth primary color', Squant. This was also the only color with it's own smell as well. Negativland also had a plugin for web-browser that allowed you to 'see' this magical fourth primary color.<p>[1]<a href="https://www.negativland.com/archives/015squant/story.html" rel="nofollow">https://www.negativland.com/archives/015squant/story.html</a><p>[2]<a href="https://en.wikipedia.org/wiki/Over_the_Edge_(radio)" rel="nofollow">https://en.wikipedia.org/wiki/Over_the_Edge_(radio)</a><p>[3]<a href="https://www.youtube.com/watch?v=lt8biSTQ7wk" rel="nofollow">https://www.youtube.com/watch?v=lt8biSTQ7wk</a>
Reminds me of The Color Out of Space.<p><a href="https://en.m.wikipedia.org/wiki/The_Colour_Out_of_Space" rel="nofollow">https://en.m.wikipedia.org/wiki/The_Colour_Out_of_Space</a>
What happens when someone with tetrachromacy looks at these same test colour tests?<p>See: <a href="https://en.wikipedia.org/wiki/Tetrachromacy" rel="nofollow">https://en.wikipedia.org/wiki/Tetrachromacy</a>
> Impossible colors or forbidden colors are supposed colors that cannot be perceived in normal seeing of light that is a combination of various intensities of the various frequencies of visible light, but are reported to be seen in special circumstances.<p>This article could use some serious copy editing.