Useful Taurus Teal

Latin ūsus, use — adjectival suffix -ful. As a color modifier, useful implies a clear-and-purpose-serving quality where the hue carries the visual register of helpful-and-supporting design-element. Sits at the crisp-and-functional end of the grid, parallel to practical and serviceable in usage.

Latin taurus, bull-of-the-zodiac. As a color modifier, taurus implies a bull-and-earth-sign-and-Venus-ruled-fixed-earth quality, the visual register of Mesopotamian-bull-and-Greek-Taurus hand-bull-and-earth-sign-and-Venus-ruled-fixed-earth Mesopotamian-bull-and-Greek-Taurus-and-Pleiades-cluster taurus-and-bull-and-earth-sign surfaces under Mesopotamian-bull-and-Greek-Taurus-and-Pleiades-cluster spring-and-April-and-May fixed-earth-sign-light. Sits at the modifier-and-zodiac end of the grid, parallel to aries and gemini in usage.

Anas crecca, the small dabbling duck whose male in breeding plumage sports a chestnut head crossed by a glossy green-blue stripe. The color refers to that stripe — the iridescent panel just behind the eye: a saturated, slightly muted blue-green with the optical depth of structural color rather than pigment. Cooler than cypress, warmer than cerulean, with the ornithological specificity of a color named for one feather of one bird.