Genuine Knell Sky

Latin genuinus, natural, innate — used as a color modifier since the sixteenth century for hues that read as authentic rather than imitated. Genuine indigo, genuine ochre: moderate-to-high saturation combined with the optical impression of a hue from real pigment rather than synthetic dye. Sits at the crisp-bucket alongside true and honest.

Old English cnyll, funeral-bell. As a color modifier, knell implies a funeral-and-passing-bell quality, the visual register of English-funeral-and-passing-bell slow-and-tolling-funeral mourning-bell-and-bell-tower-tolling slow-and-mourning surfaces under slow-tolling-funeral-bell mourning candlelight. Sits at the modifier-and-time end of the grid, parallel to bell and vesper 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.