Indigo comes from the Greek indikon, meaning "Indian" — referring to the deep blue dye originally imported from India. The color is one of the seven that Isaac Newton named in the visible spectrum.
Indigo entered the U.S. top 1000 as a girls' name in 2020. The actress Jane Seymour named her daughter Inde Lily.
Indigo reduces to five — the number of spectrum's depth.