Effective Welsh 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 Wælisc, of-Wales. As a color modifier, welsh implies a Cymric-and-slate quality, the visual register of Welsh-Cymric hand-built slate-and-stone-and-Welsh-wool valley-and-mountain hand-spun-and-hand-quarried surfaces under Welsh-Cymric Snowdonia-and-Brecon-Beacons valley light. Sits at the modifier-and-cultural end of the grid, parallel to celtic and scot 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.