Lyn Hejinian at Cabinet:

Cyan (pronounced SIGH-ann) is the color that emanates from a calm sea not far offshore on a clear day as the blue of the sky is reflected in salt water awash over yellow sand. You can see it for yourself in postcards mailed from coastal resorts or, if you are at a resort, from a vantage point somewhere above the beach—from a cliff, say, or lacking cliffs, from atop a palm tree. Various shades of cyan form the background to the ad for Swarovski (whatever that is) on page 13 of the April 2005 issue of Gourmet magazine. To create a highly saturated cyan on your own, you might pour 1/4 cup of Arm & Hammer’s Powerfully Clean Naturally Fresh Clean Burst laundry detergent onto the whites in your next load of wash (presumably Arm & Hammer adds the pigment to its product in order to provoke association with what we imagine to be the pristine purity of tropical seas). Also, you might search for “cyan” at, where a resplendent rectangle of the color is on display, along with a succinct definition: “Cyan is a pure spectral color, but the same hue can also be generated by mixing equal amounts of green and blue light. As such, cyan is the complement of red: cyan pigments absorb red light. Cyan is sometimes called blue-green or turquoise and often goes undistinguished from light blue.”

more here.