Vitreous Tunic Sky

Latin vitreus, glass-like — derived from vitrum (glass). As a color modifier, vitreous implies a clear-and-glassy quality where the hue carries the optical clarity of polished crown-glass. Sits at the crisp-and-clear end of the grid, parallel to pellucid and crystalline in usage.

Latin tunica, Roman-undergarment. As a color modifier, tunic implies a Roman-tunic-and-medieval-undergarment quality, the visual register of Roman-tunic-and-medieval-bliaut hand-Roman-tunic-and-medieval-undergarment Roman-tunic-and-medieval-bliaut-and-Carolingian-court tunic-and-Roman-tunic-and-medieval-undergarment surfaces under Roman-tunic-and-medieval-bliaut-and-Carolingian-court Republican-and-Carolingian-Aachen Roman-and-medieval-light. Sits at the modifier-and-textile end of the grid, parallel to chiton and peplos 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.