Open Mass Lagoon

Old English open, unobstructed — used as a color modifier since the eighteenth century for hues that read as airy or uncrowded. Open blue, open green: moderate saturation combined with optical spaciousness, the slight visual breath of a hue that doesn't crowd the surface it covers. Sits at the crisp-bucket center alongside clear.

Latin missa, Mass-of-the-Eucharist. As a color modifier, mass implies a Eucharistic-and-liturgical-feast quality, the visual register of Roman-Catholic-and-Anglican-Mass Eucharistic-and-liturgical-feast altar-and-vestment-and-incense liturgical-Mass surfaces under Mass-and-Eucharistic-feast altar-candle-and-incense light. Sits at the modifier-and-time end of the grid, parallel to vigil and vesper 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.