Pellucid Tower Sky

Latin pellūcidus, transparent — derived from per-lūcēre (to shine through). As a color modifier, pellucid implies a clear-and-translucent quality where the hue reads with optical clarity and minimal turbidity. Sits at the crisp-and-clear end of the grid, parallel to lucid and translucent in usage.

Latin turris, tower. As a color modifier, tower implies a tall-fortified-or-cathedral-tower quality, the visual register of Tower-of-London-and-Italian-bell-tower hand-built tall-fortified-or-bell-tower medieval-and-Renaissance-tower architectural surfaces under medieval-and-Renaissance tower-and-belfry monumental light. Sits at the modifier-and-architecture end of the grid, parallel to turret and keep 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.