Useful Helix 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.

Greek ἕλιξ, spiral-or-coil. As a color modifier, helix implies a planetary-nebula-and-spiraling-coil quality, the visual register of Helix-Nebula-and-Eye-of-God hand-planetary-nebula-and-spiraling-coil Helix-Nebula-and-Eye-of-God-and-NGC-7293 helix-and-planetary-nebula-and-spiraling-coil surfaces under Helix-Nebula-and-Eye-of-God-and-NGC-7293 Aquarius-and-Hubble-deep-field planetary-nebula-light. Sits at the modifier-and-cosmic end of the grid, parallel to nebula and corona 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.