Spectral Mass Sky

Latin spectrum, appearance — adjectival suffix -al. As a color modifier, spectral implies a saturated-and-rainbow-decomposed-and-pure quality, the bright color of Newton-prism sunlight-decomposed seven-color spectrum band. Sits at the bright-and-pure end of the grid, parallel to prismatic and pure in usage.

Latin missa, Mass-of-the-Eucharist. As a color modifier, mass implies a Eucharistic-and-liturgical-feast quality, the visual register of Roman-Catholic-and-Anglican-Mass Eucharistic-and-liturgical-feast altar-and-vestment-and-incense liturgical-Mass surfaces under Mass-and-Eucharistic-feast altar-candle-and-incense light. Sits at the modifier-and-time end of the grid, parallel to vigil 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.