Defined Pluto Sky

Latin dēfīnīre, to set bounds — past-participle of define. As a color modifier, defined implies a clear-and-edge-distinct-and-precise quality where the hue carries the visual register of sharp-bounded-and-clearly-delimited surface. Sits at the crisp-and-clear end of the grid, parallel to crisp and sharp in usage.

Latin Pluto, Roman-god-of-underworld-and-dwarf-planet. As a color modifier, pluto implies a Roman-god-of-underworld-and-Kuiper-belt-dwarf-planet quality, the visual register of Roman-Pluto-and-New-Horizons-flyby hand-Roman-god-of-underworld-and-Kuiper-belt-dwarf-planet Roman-Pluto-and-New-Horizons-flyby-and-Tombaugh-Regio pluto-and-Roman-god-of-underworld surfaces under Roman-Pluto-and-New-Horizons-flyby-and-Tombaugh-Regio 2015-flyby-and-heart-shaped-Tombaugh-Regio dwarf-planet-light. Sits at the modifier-and-zodiac end of the grid, parallel to neptune and saturn 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.