Plain Ether Ocean

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.

Greek αἰθήρ, upper-air-or-quintessence. As a color modifier, ether implies a luminiferous-and-pure-upper-air quality, the visual register of Aristotelian-quintessence-and-luminiferous-ether hand-luminiferous-and-pure-upper-air Aristotelian-quintessence-and-luminiferous-and-Newtonian ether-and-luminiferous-and-pure-upper-air surfaces under Aristotelian-quintessence-and-luminiferous-and-Newtonian celestial-spheres-and-natural-philosophy upper-air-light. Sits at the modifier-and-cosmic end of the grid, parallel to plasma and nebula in usage.

The body of saltwater that covers seventy percent of Earth's surface — a single connected mass divided by convention into Atlantic, Pacific, Indian, Southern, and Arctic. The color refers to the average reflectance of mid-depth temperate ocean: a saturated, slightly green-shifted deep blue with the optical depth of a body of water that absorbs all light below the photic zone. Deeper than mediterranean, cooler than peacock.