True blue through millennia, indigo has colorful history

The blue in today’s blue jeans is derived from a readily available synthetic dye.

Good thing, because denims would cost much, much more if manufacturers were still relying on natural indigo.  From its original source in a gland of the indigo snail, providing the color for the victory togas of Roman generals, to the ancient but still practiced use of plant indigo in Japanese wedding garments, the hue has been prized worldwide for millennia.

The role of indigo in history, science and aesthetics will be discussed tomorrow at a Penn Humanities Forum lecture with Nobel Prize-winning chemist and Cornell University professor emeritus Roald Hoffmann.  He spoke with WHYY’s Dave Heller on what he calls “The Allure of Indigo.”