What Is Indigo and Why Is It in the Color Wheel?

How Indigo Dye Was Made (The Ancient Way) 🔵 Long before chemical dyes existed, indigo was extracted from plants using pure science and patience. The process began with Indigofera plants, whose leaves contained a colorless compound called indican. First, fresh leaves were soaked and fermented in water. This fermentation broke down indican into indoxyl. Next, the liquid was vigorously stirred and aerated, allowing oxygen to react with indoxyl and form the deep blue pigment we know as indigo. The