Roughly what you see, faked with the square around it dimmed (no screen can show the real thing): a blue as dark as black, a red brighter than white, an orange more orange than any paint.
Tricks of color
Impossible colors
Stare at the × in a colored circle for 30 seconds, then look at the × in the square below it. What color do you see?
Maybe a color that can’t exist on paper or a screen, like a red brighter than white.
Why? Staring tires the cells in your eye that sense that color. When you look away, the others take over, and the mix is a color no light could make by itself.
Picture: Drawn by Science Playground, after Zowie · Wikipedia(opens in a new tab)