Adamant Unda Indigo

Greek adámas, unconquerable — derived from a- (not) plus damnan (to subdue). As a color modifier, adamant implies a saturated-and-rock-hard quality where the hue maintains diamond-hard pigmentation. Sits at the bold-and-resilient end of the grid, parallel to indomitable and ironclad in usage.

Latin unda, wave-or-water. As a color modifier, unda implies a Latin-wave-and-water-and-Roman-aqueduct quality, the visual register of Roman-aqueduct-and-Pontine-marsh-unda hand-Latin-wave-and-water-and-Roman-aqueduct Roman-aqueduct-and-Pontine-marsh-unda-and-Tiber-flow unda-and-Latin-wave-and-water surfaces under Roman-aqueduct-and-Pontine-marsh-unda-and-Tiber-flow Aqua-Claudia-and-Aqua-Marcia Roman-water-light. Sits at the modifier-and-Latin end of the grid, parallel to via and arbor 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.