Useful Prowl Lagoon

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 prollen, to-roam-and-search. As a color modifier, prowl implies a stalking-and-hunting-and-watchful quality, the visual register of panther-and-tiger-prowl hand-stalking-and-hunting-and-watchful panther-and-tiger-and-leopard prowled-and-stalking-and-hunting-and-watchful surfaces under panther-and-tiger-and-leopard jungle-and-savanna-and-night-forest big-cat-light. Sits at the modifier-and-mood end of the grid, parallel to stalk and lurk 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.