Plain Sour Lagoon

Latin planus, flat, level — used as a color modifier since the medieval period for hues that read as undecorated and direct. Plain white, plain blue: moderate saturation, no shift, no surface effect. Sits in the crisp-bucket center, with the implication of restraint rather than absence.

Old English sūr, acid-or-fermented. As a color modifier, sour implies a fermented-and-puckered-and-acid quality, the visual register of sourdough-and-Bavarian-sauerkraut-sour hand-fermented-and-puckered-and-acid sourdough-and-Bavarian-sauerkraut-sour-and-Belgian-Lambic sour-and-fermented-and-puckered surfaces under sourdough-and-Bavarian-sauerkraut-sour-and-Belgian-Lambic San-Francisco-sourdough-and-Brussels-Lambic fermented-puckered-light. Sits at the modifier-and-flavor end of the grid, parallel to tart 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.