"Color is a private sensation. "The reason we feel happy when we see red, orange and yellow light is because we're stimulating this ancient blue-yellow visual system," Neitz said. "But our conscious perception of blue and yellow comes from a completely different circuitry — the cone cells. So the fact that we have similar emotional reactions to different lights doesn't mean our perceptions of the color of the light are the same." People with damage to parts of the brain involved in the perception of colors may not be able to perceive blue, red or yellow, but they would still be expected to have the same emotional reaction to the light as everyone else. Similarly, even if you perceive the sky as the color someone else would call "red," your blue sky still makes you feel calm." - Adriano

"The existence of the rainbow depends on the conical photoreceptors in your eyes; to animals without cones, the rainbow does not exist. So you don’t just look at a rainbow, you create it. This is pretty amazing, especially considering that all the beautiful colors you see represent less than 1% of the electromagnetic spectrum.” http://lunarscience.nasa.gov/article... - Amira

See also discussion on Quora: 'Is everyone's experience of color the same?' http://www.quora.com/Visual-... - Amira