Effective Sleet Lagoon

Latin effectīvus, productive — adjectival suffix -ive. As a color modifier, effective implies a clear-and-purpose-achieving quality where the hue carries the visual register of successful-task-completion design-element. Sits at the crisp-and-functional end of the grid, parallel to practical and useful in usage.

Middle English slete, icy-rain-or-snow-rain-mix. As a color modifier, sleet implies an icy-rain-and-half-frozen-and-driven quality, the visual register of North-Sea-and-Yorkshire-Moors-sleet hand-icy-rain-and-half-frozen-and-driven North-Sea-and-Yorkshire-Moors-sleet-and-Pennine-pass sleet-and-icy-rain-and-half-frozen surfaces under North-Sea-and-Yorkshire-Moors-sleet-and-Pennine-pass Yorkshire-Moors-and-Pennine-Way-and-Cleveland-Hills North-Sea-front-light. Sits at the modifier-and-weather end of the grid, parallel to hail and rime 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.