Thunderous Umber Ultramarine

Old English thunor, thunder — adjectival suffix -ous, sharing root with German Donner and Old Norse Þórr (Thor). As a color modifier, thunderous implies a deep-and-rumbling-and-imposing-cool quality, the dark cool-gray of cumulonimbus-tower-base storm-cloud directly overhead. Sits at the deep-and-turbulent end of the grid, parallel to stormy with auditory-resonance overtone.

Latin umbra, shadow. As a color modifier, umber implies a shadowed-and-Umbrian-earth-pigment quality, the visual register of Caravaggio-and-Rembrandt-umber hand-shadowed-and-Umbrian-earth-pigment Caravaggio-and-Rembrandt-and-Vermeer-Dutch-Golden-Age umbered-and-shadowed-and-deep-glazed surfaces under Caravaggio-and-Rembrandt-and-Vermeer chiaroscuro-and-tenebrist-and-glazed studio-window-light. Sits at the modifier-and-mood end of the grid, parallel to shade and gloom 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.