Open Sigh Lagoon

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.

Middle English sighen, to-breathe-out-audibly. As a color modifier, sigh implies a breathed-out-and-released-and-wistful quality, the visual register of Romantic-poet-and-pining-lover-sigh hand-breathed-out-and-released-and-pining Romantic-poet-and-pining-lover-and-bedside-vigil sighed-and-released-and-breathed-out surfaces under Romantic-poet-and-pining-lover candle-lit-and-bedside-vigil window-and-balcony-light. Sits at the modifier-and-mood end of the grid, parallel to yearn and brood in usage.

A shallow body of saltwater partially or fully enclosed by a barrier — coral atoll lagoons in the Pacific, Venice's Laguna Veneta, the Florida Keys' backcountry. The color refers to the average reflectance of a calm tropical lagoon at midday: a saturated, slightly muted blue-green with the optical clarity of shallow water over white sand. Brighter than reef, cooler than aquamarine, with the postcard weight of a Pacific atoll seen from above.