How to see imaginary colors
I will now show you a way to see colors that cannot exist in nature.
To do this I'm going to hack your brain, but don't worry, you won't feel a thing, and it doesn't involve taking any controlled substance.
Ready? Ok, say you want to see a green more intense than any green that has ever existed on the face of earth(and in fact the universe).
Stare at the top right dot (in the magenta field) and count to fifty. Try not to move your eyes too much.Then look very quickly at the dot in the green field.
And there you have it. A shade of green you have never seen before, and will only see again in this or a similar test.
What's happening? When you stare at any color for a while, you're eye's sensitivity to it decreases, and the sensitivity to the complemetn (i.e. opposite, in a sense which trascends the point of this post). Well to make a long story short, each row has one of the Red-Green-Blue primaries on the left, and its complementary color on the right.
When you stare at magenta (blue + red), the blue and red light receptors on your retina became fatigued and lost sensitivity, while the green ones did not (no green light in magenta).
So when you looked over quickly, your brain received something it usually NEVER gets: a signal from the eye with almost nothing but inputs from the green cell. No object can "be" that color, its only by priming your nervous system in a certain way that you get to see it.
You should rest your eyes to reset the mechanism before trying it again, especially if you want to try the reverse pair (5 minutes should be fine). In my experience, you don't have to wait quite as long to try any of the other pairs.
Hope you liked this. I learn a lot about colors and eyesight in general by reading this book. I would reccomend it immensely (the book has a short chapter on how colors work, though this particular factoid came from wikipedia, and the graphic is by yours truly).