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
George Palmer (colour theorist) George Palmer (colour theorist) George Palmer (ca. 1746 – March 3, 1826), also known as George Giros de Gentilly, named Palmer) was an English dye chemist, colour theorist, inventor, and soldier. He is best known for his conjectures about colour vision and colour blindness. According to statements in his Copenhagen obituary, Palmer was born on an English ship to English parents of Catholic faith. Owing to the 18th century restrictions on activities of English Catholics, Palmer, as many others of his time, lived a double life between England and France. Nothing is known about his early years. Palmer reports to