Crimson & Emerald & Violet

Emerald (hue 140°, vivid, luminous) and Violet (hue 270°, deep, electric) are 130° apart — a wide split-complementary spread across the cool spectrum. Violet is the highest-frequency visible color (approximately 380-450 nm wavelength) and the most spectrally extreme purple — more electric and more luminescent under UV light than any other visible color. Against Emerald's jewel-green luminosity, Violet creates the most dramatic cool contrast possible within the cool arc of the spectrum. Against Crimson's warm passionate red, the palette becomes the most dramatically luminescent and most naturally psychedelic.

The palette is the visual world of the Aurora Borealis (Northern Lights — Aurora Borealis — from Latin: Aurora — goddess of the dawn; Borealis — of the north) and specifically the most vivid and most multi-colored aurora displays observed at high latitudes (65°-80° North). The aurora palette: the deep vivid crimson-to-red of the highest-altitude aurora bands (the rare, deep-red oxygen aurora — produced by excited atomic oxygen at altitudes above approximately 200 km, where oxygen atoms are rarefied enough that collisions are infrequent and the excited state persists long enough to emit at the 630.0 nm red-to-crimson wavelength); the vivid emerald-green of the most characteristic and most commonly seen aurora color (the green oxygen aurora — produced at approximately 100-200 km altitude, where the most common aurora display creates vivid emerald-to-green curtains from the 557.7 nm green oxygen emission line — the most efficient and most common aurora emission); and the deep electric violet-to-blue of the nitrogen aurora (produced primarily by ionized molecular nitrogen — N₂⁺ — at altitudes of approximately 100 km or below, creating violet-to-blue curtains most often visible in the lower margins of auroral displays).