How do we know we all see the same colors? The short answer is that we don’t know, and according to some new research, there’s a good chance we don’t in fact all see the same colors. Via Marginal Revolution:
Anyone with normal color vision agrees that blood is roughly the same color as strawberries, cardinals and the planet Mars. That is, they’re all red. But could it be that what you call “red” is someone else’s “blue”? Could people’s color wheels be rotated with respect to one another’s?
“That is the question we have all asked since grade school,” said Jay Neitz, a color vision scientist at the University of Washington. In the past, most scientists would have answered that people with normal vision probably do all see the same colors. The thinking went that our brains have a default way of processing the light that hits cells in our eyes, and our perceptions of the light’s color are tied to universal emotional responses. But recently, the answer has changed.
“I would say recent experiments lead us down a road to the idea that we don’t all see the same colors,” Neitz said.
Another color vision scientist, Joseph Carroll of the Medical College of Wisconsin, took it one step further: “I think we can say for certain that people don’t see the same colors,” he told Life’s Little Mysteries.
One person’s red might be another person’s blue and vice versa, the scientists said. You might really see blood as the color someone else calls blue, and the sky as someone else’s red. But our individual perceptions don’t affect the way the color of blood, or that of the sky, make us feel.
More here.