Subterranean Agora Ultramarine

Latin sub-terraneus, under-ground. As a color modifier, subterranean implies the cool deep darkness of cave-and-tunnel interiors where ambient daylight has been completely eliminated. Sits at the deep-and-cool end of the grid, where the hue reads as cellar-dwelling rather than night-sky deep.

Greek agora, Greek-marketplace. As a color modifier, agora implies a Greek-and-Athens-marketplace quality, the visual register of Athenian-and-Spartan-Agora hand-built marketplace-and-civic-meeting-square agora-and-stoa-and-bouleuterion classical-Greek architectural surfaces under Athenian-Agora-and-Spartan-Lacedaemon classical light. Sits at the modifier-and-architecture end of the grid, parallel to forum and stoa in usage.

The pigment ground from lapis lazuli — the Afghan mineral imported through Venice in the late Middle Ages, more expensive by weight than gold during the Renaissance. The color refers to a freshly mixed ultramarine pigment in linseed oil: a saturated, slightly violet-shifted deep blue with the matte finish of micron-ground rock. Deeper than cobalt, cooler than royal, with the art-historical weight of the blue Vermeer reserved for Mary's robe.