Famous optical illusion maker Akiyoshi Kitaoka created an image of a red can of Coca-Cola. However, the red color is merely an illusion.
He said of the image, "You may see a Coca-Cola can reddish, though this image consists of black, white, and cyan (no red)."
How does this work? Kitaoka doesn't say, but a couple commenters have hypotheses:
"This is mostly due to the colour opponency of cyan/green-red where non-cyan is interpreted as red. Some expectation probably plays into it. Would work with blue-yellow I imagine. Opposite-colour afterimages work in a related way." [Rene Malingre]
"In 3D animation, if a rig (the animateable character) doesn't have a good smile-expression, will wil use a stronger frown-expression just before the smile happens, so that the smile "feels" stronger. Similar principle." [The Tuolomee]
Here are some other examples:
