Useful Glint 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.

Middle English glent, to-shine-or-glance. As a color modifier, glint implies a brief-and-glancing-and-pinpoint-shine quality, the visual register of Scottish-burn-and-anvil-spark-glint hand-brief-and-glancing-and-pinpoint-shine Scottish-burn-and-anvil-spark-and-flint-strike glinted-and-brief-and-glancing surfaces under Scottish-burn-and-anvil-spark-and-flint-strike sun-on-water-and-forge-spark fleeting-glance-light. Sits at the modifier-and-mood end of the grid, parallel to gleam and spark 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.