Indigo is a deep and rich color close to the color wheel blue (a primary color in the RGB color space), as well as to some variants of ultramarine. It is traditionally regarded as a color in the visible spectrum, as well as one of the seven colors of the rainbow: the color between violet and blue; however, sources differ as to its actual position in the electromagnetic spectrum.
The color indigo is named after the indigo dye derived from the plant Indigofera tinctoria and related species.
The first known recorded use of indigo as a color name in English was in 1289.
A purplish-blue colour
An indigo-colored dye obtained from certain plants (the indigo plant or woad), or a similar synthetic dye.
An indigo plant, such as from species in genera Indigofera, Amorpha (false indigo), Baptisia (wild indigo), and ver=161009 and Dalea (indigo bush).
having a deep purplish-blue colour
A bluish-purple colour.
Viola, a genus of fragrant plants with white, purple or yellow flowers.
Any of several plants that look like the plants of the genus Viola but are taxonomically unrelated to them.
Having a bluish-purple colour.