Useful Wraith 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.

Scots wraith, ghost-or-apparition. As a color modifier, wraith implies a ghostly-and-pale-and-apparitional quality, the visual register of Highland-Scots-and-Border-Ballad-wraith hand-ghostly-and-pale-and-apparitional Highland-Scots-and-Border-Ballad-and-Hebridean wraith-and-ghostly-and-pale surfaces under Highland-Scots-and-Border-Ballad-and-Hebridean moonlit-and-mist-shrouded-and-pale graveyard-and-tarn-light. Sits at the modifier-and-mood end of the grid, parallel to pall and gloam 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.