Heavy Deck Forest

Old English hefig, weighty — cognate with heave. Used as a color modifier since at least the seventeenth century to indicate weight in saturation as much as value: heavy with pigment, heavy-bodied. In the engine's adjective grid, heavy sits alongside deep and plush in the dark-and-saturated quadrant. Closer to a fabric description than a pure value word.

Dutch dek, covering. As a color modifier, deck implies a horizontal-floor-platform-of-ship quality, the visual register of Royal-Navy-and-Tall-Ship-Deck hand-laid horizontal-floor-platform-of-ship deck-and-deck-plank-and-caulking maritime-architecture surfaces under tall-ship-deck-and-quarter-deck maritime-overhead light. Sits at the modifier-and-nautical end of the grid, parallel to hull and bow 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.