Gaudy Sill Sky

Middle English gaude, trick / showy ornament — adjectival suffix -y. As a color modifier, gaudy implies a saturated-and-cheaply-bright-and-overdone quality, the bright color of carnival-and-fairground novelty-attraction painted-and-lit decoration. Sits at the bright-and-flamboyant end of the grid, parallel to garish and lurid in usage.

Old English syll, threshold-beam. As a color modifier, sill implies a horizontal-bottom-of-window-or-door quality, the visual register of English-cottage-and-farmhouse hand-cut horizontal-window-and-door bottom-edge sill-and-threshold architectural surfaces under English-cottage-and-farmhouse sill-edge light. Sits at the modifier-and-architecture end of the grid, parallel to lintel and truss 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.