Direct Ruff 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 English ruffe, Elizabethan-pleated-collar. As a color modifier, ruff implies a starched-and-Elizabethan-pleated-collar quality, the visual register of Elizabethan-and-Spanish-Habsburg-ruff hand-starched-and-Elizabethan-pleated-collar Elizabethan-and-Spanish-Habsburg-ruff-and-Holbein-portrait ruff-and-starched-and-Elizabethan-pleated-collar surfaces under Elizabethan-and-Spanish-Habsburg-ruff-and-Holbein-portrait Tudor-and-Spanish-Habsburg-court starched-collar-light. Sits at the modifier-and-textile end of the grid, parallel to gown and frock 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.