Johann Friedrich Wilhelm Adolf von Baeyer was a German chemist who synthesised indigo and developed a nomenclature for cyclic compounds. He was ennobled in the Kingdom of Bavaria in 1885 and was the 1905 recipient of the Nobel Prize in Chemistry.

Indigo dye is an organic compound with a distinctive blue color. Indigo is a natural dye extracted from the leaves of some plants of the Indigofera genus, in particular Indigofera tinctoria. Dye-bearing Indigofera plants were commonly grown and used throughout the world, particularly in Asia, with the production of indigo dyestuff economically important due to the historical rarity of other blue dyestuffs.