indigo
adj.adj. having a dark blue-purple color, like the sky just before it gets completely dark.
adj. describing a deep, rich color between blue and violet in the visible spectrum. Often used to describe dyes or the night sky.
She wore a beautiful indigo dress to the party.
The artist mixed deep blues and purples to capture the indigo hues of the ocean at dusk.
Historically, indigo was a highly prized natural dye extracted from plants, serving as a primary export for several colonial economies before the advent of synthetic alternatives.
16th century (as indico, modern spelling from the 17th century), Spanish índigo, Portuguese endego (modern índigo), or Dutch (via Portuguese) indigo, all from Latin indicum (“indigo”), from Ancient Greek ἰνδικόν (indikón, “Indian dye”), from Ἰνδία (Indía). Doublet of Indic.
Commonly used as a color descriptor before a noun; can also function as a noun when referring to the dye itself.