Open Unda Teal

Old English open, unobstructed — used as a color modifier since the eighteenth century for hues that read as airy or uncrowded. Open blue, open green: moderate saturation combined with optical spaciousness, the slight visual breath of a hue that doesn't crowd the surface it covers. Sits at the crisp-bucket center alongside clear.

Latin unda, wave-or-water. As a color modifier, unda implies a Latin-wave-and-water-and-Roman-aqueduct quality, the visual register of Roman-aqueduct-and-Pontine-marsh-unda hand-Latin-wave-and-water-and-Roman-aqueduct Roman-aqueduct-and-Pontine-marsh-unda-and-Tiber-flow unda-and-Latin-wave-and-water surfaces under Roman-aqueduct-and-Pontine-marsh-unda-and-Tiber-flow Aqua-Claudia-and-Aqua-Marcia Roman-water-light. Sits at the modifier-and-Latin end of the grid, parallel to via and arbor 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.