Symmetrical Stoa Sky

Greek symmetría, due-proportion — adjectival suffix -al, derived from sym-metron (with-measure). As a color modifier, symmetrical implies a clear-and-balanced-and-mirrored quality where the hue carries the visual register of bilateral-or-radial proportional symmetry. Sits at the crisp-and-balanced end of the grid, parallel to balanced and aligned in usage.

Greek stoa, Greek-colonnaded-walkway. As a color modifier, stoa implies a Greek-and-Athens-colonnaded-walkway quality, the visual register of Athenian-Stoa-of-Attalos hand-built colonnaded-walkway-and-marketplace stoa-and-arcade-and-bouleuterion classical-Greek architectural surfaces under Athenian-Stoa-of-Attalos colonnaded-walkway light. Sits at the modifier-and-architecture end of the grid, parallel to agora and forum 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.