Saturated Ether Indigo

From the Latin saturatus, past participle of saturare, to fill. A technical color term in modern usage — saturation is one of the three axes of HSL (with hue and lightness). As a modifier, saturated implies that the hue is at or near its maximum chromatic intensity. Sits at the bold-and-bright top of the grid.

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.

Indigofera tinctoria, the South Asian legume whose leaves yield the deep blue dye that has clothed humanity for at least four thousand years — Egyptian linen, Mayan textile, the slave-grown plantations of Carolina. The color refers to a freshly indigo-dyed cotton thread: a saturated, slightly violet-shifted deep blue with the slight lustre of a fiber surface oxidized in air. Deeper than cobalt, cooler than royal.