An article from last week's New York Times describes the importance of the color red, just in time for Valentine's Day. In How Do We See Red? Count the Ways Natalie Angier talks about various meanings of the color red, including "shades of life, death, fury, shame, courage, anguish, pride", and not only for humans:
"Red is the premier signaling color in the natural world, variously showcasing a fruitful bounty, warning of a fatal poison or boasting of a sturdy constitution and the genes to match."
Angier quotes Dr. Nicholas Humphrey, a philosopher at the London School of Economics and the author of Seeing red : a study in consciousness: "Our visual system was shaped by colors already in use among many plants and animals, and red in particular stands out against the green backdrop of nature," he said. "If you want to make a point, you make it in red."
Happy Valentine's Day!