Certain Atrium Forest

Latin certus, fixed / sure — sharing root with English concern and certify. As a color modifier, certain implies a saturated-and-unambiguous quality where the hue declares its character without hesitation. Sits at the bold-and-confident end of the grid, parallel to assured and decisive in usage.

Latin atrium, Roman-house-courtyard. As a color modifier, atrium implies a Roman-and-modern-courtyard-with-skylight quality, the visual register of Roman-Pompeii-and-modern-Mid-Century-Modern-atrium hand-built central-courtyard-with-skylight atrium-and-impluvium-and-courtyard architectural surfaces under Roman-and-Mid-Century-Modern atrium-skylight light. Sits at the modifier-and-architecture end of the grid, parallel to loggia and quad in usage.

The dense canopy of a temperate or tropical woodland — oak, beech, pine, eucalyptus, mahogany — wherever leaves close above to filter the light below. Forest green refers to the average reflectance of a healthy mid-summer canopy seen from below: a saturated, slightly muted green with the matte finish of layered chlorophyll. Deeper than fern, cooler than olive, with the ecological weight of a word that has named every wooded biome on Earth.