Bright Hail Sky

Old English beorht, shining, luminous — cognate with the German Bracht, splendor. Applied to color since at least the medieval period for hues that read as luminous: not just light in value but optically active, as if scattering more light back than a dimmer color of the same lightness would. Sits at the bright-bucket center alongside vivid and brilliant.

Old English hægl, hail-stones. As a color modifier, hail implies a hail-stone-and-clattering-and-spring-thunderstorm quality, the visual register of prairie-and-summer-thunderhead-hail hand-hail-stone-and-clattering-and-spring-thunderstorm prairie-and-summer-thunderhead-hail-and-Great-Plains hail-and-hail-stone-and-clattering surfaces under prairie-and-summer-thunderhead-hail-and-Great-Plains Tornado-Alley-and-Kansas-Oklahoma-storm-cell prairie-thunderhead-light. Sits at the modifier-and-weather end of the grid, parallel to sleet and flurry 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.