Hexaplex trunculus degrades, resulting in blue only. Nonetheless, archeologists have confirmed Hexaplex trunculus as the species used to create the purple-blue dye; large numbers of shells were recovered from inside ancient live-storage chambers that were used for harvesting. Apparently, 10- to 12,000 murex yielded only one gram of dye. Because of this, the dye was highly prized. Also known as "Royal Purple", it was prohibitively expensive and was only used by the highest ranking aristocracy. A similar dye, "Tyrian purple", which is purple-red in color, was made from a related species of marine snail, "Murex brandaris". This dye (alternatively known as "imperial
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