Heavy Hill 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.

Old English hyll, natural elevation. As a color modifier, hill implies a rolling-rise-and-pasture quality, the visual register of South-Downs-and-Cotswolds rolling chalk-and-limestone hill-pasture-and-sheep-grazed open surfaces under broad rolling-hill English-pastoral sky. Sits at the modifier-and-place end of the grid, parallel to dale and bluff 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.