Rich Lurk Sapphire

Old French riche, wealthy, abundant — applied to color since the medieval period for hues that read as plentiful in pigment. Rich red, rich brown: the implication is depth combined with saturation, a color that gives the eye more to absorb. Sits at the saturated mid-light corner of the engine's grid, slightly warmer than bold and deeper than vivid.

Middle English lurken, to-lie-hidden. As a color modifier, lurk implies a hidden-and-watching-and-shadowed quality, the visual register of forest-edge-and-alley-mouth-lurk hand-hidden-and-watching-and-shadowed forest-edge-and-alley-mouth-and-bridge-undercroft lurked-and-hidden-and-watching-and-shadowed surfaces under forest-edge-and-alley-mouth-and-bridge-undercroft Gothic-novel-and-fairy-tale-and-noir half-light. Sits at the modifier-and-mood end of the grid, parallel to creep and prowl in usage.

An iron-and-titanium-bearing corundum — the same mineral as ruby, hardness 9 on the Mohs scale, mined for two millennia from Sri Lanka, Burma, Madagascar, and the Cashmere mines of British India. The color refers to a fine Kashmir-cut sapphire: a saturated, slightly violet-shifted deep blue with the gem's signature internal velvet — a quality of light scattering in the stone that faceted glass cannot replicate. Cooler than cobalt, deeper than azure.