Tyrian purple the Iles Purpuraires at Mogador, in Morocco. The sea snail harvested at this western Moroccan dye production facility was "Hexaplex trunculus" (mentioned above) also known by the older name "Murex trunculus". This second species of dye murex is found today on the Mediterranean and Atlantic coasts of Europe and Africa (Spain and Portugal, Morocco, and the Canary Islands). The colour-fast (non-fading) dye was an item of luxury trade, prized by Romans, who used it to colour ceremonial robes. Used as a dye, the color shifts from blue (peak absorption at 590 nm, which is yellow-orange) to reddish-purple (peak absorption at
British Colour Council each colour. BCC colour codes define colours as varying by hue, tone and intensity, and were originally designed for use in the textile dye industry. The colour names given by the BCC were particularly descriptive and often referred to flora or fauna, with titles such as Larkspur ("No. 196"), Forget-Me-Not ("No. 84"), Bee Eater Blue, Kermes, and Squirrel. The codes of the BCC became standards for identifying colours used in everything from the Royal Horticultural Society, to British government planning commission maps, the British Army, Royal Institute of British Architects, and the Royal Mail. BCC codes, due to their subtlety