Heavy Murex

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.

Bolinus brandaris and Hexaplex trunculus — the two principal Mediterranean sea-snail genera whose hypobranchial-gland secretion was processed into Tyrian purple dye for two-and-a-half millennia. Murex color refers to a freshly Murex-dye-bath-emerged Phoenician trade-textile: a saturated, slightly cool deep violet with the matte finish of multi-bath shellfish-dye on hand-loomed Levantine wool. The Latin murex gives English murexide, a synthetic violet-red dye.