Brilliant Lone Sky

From the Italian brillante, sparkling — used as a color modifier since the seventeenth century for hues that read as optically active beyond their literal saturation. Brilliant green, brilliant blue: the implication is luminance combined with the slight sparkle of a high-refractive surface. Sits at the bright-bucket center alongside vivid and bright.

Middle English lone, shortened from alone. As a color modifier, lone implies a solitary-and-singular-and-isolated quality, the visual register of Caspar-David-Friedrich-Wanderer-and-lone-pine hand-solitary-and-singular-and-isolated Caspar-David-Friedrich-Wanderer-and-lone-pine-and-Romantic-vista loned-and-solitary-and-singular-and-isolated surfaces under Caspar-David-Friedrich-Wanderer-and-lone-pine-and-Romantic-vista mountaintop-and-empty-shore single-figure-light. Sits at the modifier-and-mood end of the grid, parallel to void and drear in usage.

The blue of a clear sky at noon — produced by Rayleigh scattering, the preferential dispersion of shorter wavelengths through atmospheric molecules. Air itself is colorless; the color we see is sunlight scattered toward our eyes by every cubic kilometer above. The reference shade is mid-latitude noon under a high pressure system: a clean, slightly green-shifted blue with the luminous depth of light scattered across an entire hemisphere of air.