Indigo
deep shade of blue
Indigo is a term used for a number of hues in the region of blue. The word comes from the ancient dye of the same name. The term "indigo" can refer to the color of the dye, various colors of fabric dyed with indigo dye, a spectral color, one of the seven colors of the rainbow as described by Sir Isaac Newton, or a region on the color wheel, and can include various shades of blue, ultramarine, and green-blue. Since the web era, the term has also been used for various purple and violet hues identified as "indigo", based on use of the term "indigo" in HTML web page specifications.
The word "indigo" comes from the Latin word indicum, meaning "Indian", as the naturally based dye was originally exported to Europe from India.
The Early Modern English word indigo referred to the dye, not to the color (hue) itself, and indigo is not traditionally part of the basic color-naming system.
The first known recorded use of indigo as a color name in English was in 1289. Due to the extensive knowledge of indigo cultivation by enslaved West Africans, indigo became a major cash crop in the American colonies.
Newton regarded indigo as a color in the visible spectrum, as well as one of the seven colors of the rainbow: the color between blue and violet; however, sources differ as to its actual position in the electromagnetic spectrum. Some later scientists have concluded that what Newton called "blue" was what is now called cyan or blue-green; and what Newton called "indigo" was what is now called blue.
“Indigo” enters the record as deep shade of blue. Crown Archives preserves that source wording while asking what Indigo, deep and shade can confirm, complicate or overturn.
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The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Sep 18, 2026. The linked authority identifier is Q5967009. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1289.
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This entry incorporates text from “Indigo” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.