Reposeful Vesper Lagoon

Latin repōnere, to put back — adjectival suffix -ful. As a color modifier, reposeful implies a clear-and-restful-and-still quality, the calm color of pre-modern monastic cloister-and-refectory meditative-and-silent interior architecture. Sits at the crisp-and-calm end of the grid, parallel to peaceful and placid in usage.

Latin vespera, evening. As a color modifier, vesper implies an evening-prayer-and-dusk quality, the visual register of Roman-Catholic-and-Orthodox-Vespers evening-prayer-and-dusk hour-of-day evening-prayer-and-incense liturgical surfaces under Vespers-and-Compline ecclesiastical-evening candlelight. Sits at the modifier-and-time end of the grid, parallel to eve and knell 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.