Effective Tart 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.

Old English teart, sharp-or-acid-tasting. As a color modifier, tart implies a sharp-acid-and-fruit-puckered quality, the visual register of Bramley-apple-and-rhubarb-tart hand-sharp-acid-and-fruit-puckered Bramley-apple-and-rhubarb-tart-and-Yorkshire-orchard tart-and-sharp-acid-and-fruit-puckered surfaces under Bramley-apple-and-rhubarb-tart-and-Yorkshire-orchard Yorkshire-orchard-and-Kentish-Garden-of-England puckered-orchard-light. Sits at the modifier-and-flavor end of the grid, parallel to sour and tang 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.