Symmetrical Aztec 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.

Nahuatl Aztēcatl, one-from-Aztlán. As a color modifier, aztec implies a Mexica-and-Tenochtitlan-Imperial quality, the visual register of Aztec-Empire-of-Tenochtitlan hand-built basalt-and-obsidian-and-feather-and-codex Aztec-Imperial-and-Mexica-tribute surfaces under high-altitude Tenochtitlan Aztec-Empire central-Mexico mid-altitude light. Sits at the modifier-and-cultural end of the grid, parallel to inca and toltec 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.