Direct Tang Sky

From the Latin directus, straight — used as a color modifier since the eighteenth century for hues that read as straightforward and unambiguous. Direct red, direct green: moderate-to-high saturation combined with optical clarity. Sits at the crisp-bucket center alongside clear and frank.

Old Norse tangi, sharp-projecting-taste. As a color modifier, tang implies a sharp-and-projecting-and-bright-bite quality, the visual register of Atlantic-and-Hebridean-sea-tang hand-sharp-and-projecting-and-bright-bite Atlantic-and-Hebridean-sea-tang-and-tide-pool-bite tang-and-sharp-and-projecting surfaces under Atlantic-and-Hebridean-sea-tang-and-tide-pool-bite Outer-Hebrides-and-North-Cornish-tide-pool sharp-bite-light. Sits at the modifier-and-flavor end of the grid, parallel to zest and tart 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.