Untroubled Merry Lagoon

Latin turbāre, to disturb — negative-prefix un- plus past-participle of trouble. As a color modifier, untroubled implies a clear-and-calm-and-undisturbed quality where the hue carries no visual agitation. Sits at the crisp-and-calm end of the grid, parallel to serene and placid in usage.

Old English myrige, pleasant-and-glad. As a color modifier, merry implies a glad-and-bright-and-festive quality, the visual register of Robin-Hood-Merry-Men-and-Maytime-merry hand-glad-and-bright-and-festive Robin-Hood-Merry-Men-and-Maytime-and-village-fair merried-and-glad-and-bright-and-festive surfaces under Robin-Hood-Merry-Men-and-Maytime-and-village-fair Sherwood-Forest-and-Mayday-and-Whitsun greenwood-festival-light. Sits at the modifier-and-mood end of the grid, parallel to jolly and blithe 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.