Plain Night 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 niht, darkness-and-sleep. As a color modifier, night implies a moonlit-or-star-lit-dark quality, the visual register of clear-sky moonlit-and-star-lit atmospheric Rayleigh-scattered low-light surfaces against deep blue-black night-sky horizon. Sits at the modifier-and-time end of the grid, parallel to eve and yore 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.