These are great sidelong glance readings in the time of Corona. In addition, check out this 1995 New York Times article about Theroux' second color book and how easy one can be found to have not sourced their quotes correctly.
Rulers of the ancient Mediterranean loved Tyrian purple. Roman magistrates wore white togas with a purple stripe. Emperors wore solid purple with a gold stripe as a sign of victory. But the colorful dye was exceedingly hard to get, as it was derived from Murex sea snails, which excrete the bromine compound to protect their eggs and ward off an attack.
For a single ounce of color, manufacturers had to milk or crush 250,000 gastropods. Once they’d collected the snail’s secretions, they placed the dye in a vat of urine and fermented it for 10 days, according to Kassia St. Clair’s book The Secret Lives of Color. Once they applied it to fabric, its brilliance reportedly never faded.
But the elaborate process was eventually Tyrian purple’s downfall. By the time Constantinople fell to the Turks in 1453, the Byzantine emperors could no longer afford to source the dye, according to St. Clair. The recipe was lost until 1856, when a French marine biologist rediscovered the snail species and their signature hue.