Glowering Welsh Ultramarine

Middle English gloweren, to stare angrily — present-participle of glower, sharing root with glower and gloom. As a color modifier, glowering implies a deep-and-warm-and-glowering-resentful quality, the dark warm-orange of furnace-mouth-and-Volcanic-vent embered glow. Sits at the deep-and-warm end of the grid, parallel to smouldered and hellish.

Old English Wælisc, of-Wales. As a color modifier, welsh implies a Cymric-and-slate quality, the visual register of Welsh-Cymric hand-built slate-and-stone-and-Welsh-wool valley-and-mountain hand-spun-and-hand-quarried surfaces under Welsh-Cymric Snowdonia-and-Brecon-Beacons valley light. Sits at the modifier-and-cultural end of the grid, parallel to celtic and scot 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.