Antiseptic Unda Sky

Greek anti- (against) plus sēptikós (putrefying) — adjectival suffix -ic. As a color modifier, antiseptic implies a clear-and-disinfected-and-clinical quality, the crisp color of medical-laboratory and operating-theater hand-scrub-and-sanitizer surfaces. Sits at the crisp-and-clean end of the grid, parallel to sterile and sanitary in usage.

Latin unda, wave-or-water. As a color modifier, unda implies a Latin-wave-and-water-and-Roman-aqueduct quality, the visual register of Roman-aqueduct-and-Pontine-marsh-unda hand-Latin-wave-and-water-and-Roman-aqueduct Roman-aqueduct-and-Pontine-marsh-unda-and-Tiber-flow unda-and-Latin-wave-and-water surfaces under Roman-aqueduct-and-Pontine-marsh-unda-and-Tiber-flow Aqua-Claudia-and-Aqua-Marcia Roman-water-light. Sits at the modifier-and-Latin end of the grid, parallel to via and arbor 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.