Indigo: Produces distinctive blue in shades from pale azure to dark navy, almost black

Source: Powder form or chips - Can grow the plant in your backyard or potted indoors

The organic compound for Indigo is extracted from the plant native to India producing a true natural and distinctive indigo. This particular plant yields much more dye than other plants in the same family.  A variety of other plants altogether have produced a blue over the centuries but none comparable to Indigo. The word Indigo comes from the Latin for "Indian" as in India. It's also one of the oldest dyes used in Japan and in Greco-Roman times. The colour "Indigo" in the English language first appeared in 1289.

Because blue dyes were once rare it was known as Blue Gold, a high value trading commodity. It dates back to 4000 B.C. The oldest dyed fabric found dates back over 6,000 years ago. In the seventh century B.C.,  a tablet in Babylon describes a recipe for dyeing wool.

By the 17th and 18th centuries, Spanish explorers discovered an American species of Indigo.  Production of Indigo flourished in South Carolina, U.S. beginning in the late 1700's. The global demand exploded by the late 1800's. In India more than 2,700 square miles of Indigo fields are cultivated. While most Indigo now comes from Peru.

Indigo is not soluble in water. To be dissolved and extracted , it must undergo a change in its natural make-up through a dye-bath solution process. First used in the late 1800's on denim jeans and later when an easier method of synthesis was developed in 1901. Several variations of the process are still used today. And still known for dying "denim" jeans.