Open Terra Turquoise

Old English open, unobstructed — used as a color modifier since the eighteenth century for hues that read as airy or uncrowded. Open blue, open green: moderate saturation combined with optical spaciousness, the slight visual breath of a hue that doesn't crowd the surface it covers. Sits at the crisp-bucket center alongside clear.

Latin terra, earth-or-land. As a color modifier, terra implies a earth-globe-and-loamy-and-grounded quality, the visual register of Pale-Blue-Dot-and-Apollo-Terra hand-earth-globe-and-loamy-and-grounded Pale-Blue-Dot-and-Apollo-and-Earthrise terra-and-earth-globe-and-loamy-and-grounded surfaces under Pale-Blue-Dot-and-Apollo-and-Earthrise lunar-orbit-and-deep-space earth-globe-light. Sits at the modifier-and-cosmic end of the grid, parallel to luna and sol in usage.

The hydrated copper-aluminum phosphate mined in Persia and the American Southwest for thousands of years — the firuze of Iran, the chalchihuitl of Mesoamerica, the heart of Pueblo and Navajo silverwork. The color refers to a fine Sleeping Beauty turquoise from Arizona: a saturated, slightly green-shifted blue with the slight matrix of host-rock veining. Brighter than persian, lighter than cerulean.