Sunlit Gloom Sky

Old English sunne (sun) plus past-participle līehted. As a color modifier, sunlit implies a saturated-and-direct-sunlight-illuminated quality, the bright color of southern-Mediterranean and Greek-island afternoon-sun direct-illumination surface emission. Sits at the bright-and-warm end of the grid, parallel to radiant and brilliant in usage.

Middle English gloumen, to-look-sullen. As a color modifier, gloom implies a sullen-and-darkened-and-overcast quality, the visual register of Northumbrian-moor-and-Scottish-glen-gloom hand-sullen-and-darkened-and-overcast Northumbrian-moor-and-Scottish-glen-and-Yorkshire-dale gloomed-and-darkened-and-overcast surfaces under Northumbrian-moor-and-Scottish-glen overcast-and-low-cloud heather-and-bracken-light. Sits at the modifier-and-mood end of the grid, parallel to murk 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.