A dye obtained from a species of Indigofera, particularly anil (Indigofera anil), a tropical American shrub, and Indigo tinctoria, a shrubby perennial growing to 2·5 m/8 ft; leaves pinnate; pea-flowers red, in short clusters. It was formerly cultivated in India and Sumatra, but is now little grown, since the demand for natural indigo virtually ceased following the introduction of aniline dyes. At first widely used on wool, silk, and cotton, it is now mainly used to dye the warp yarns of denim. (Family: Leguminosae.)
Distinction between four shades of indigo
Like many other colors (orange and violet are the most well-known), indigo gets its name from an object in the natural world—the plant named indigo once used for dyeing cloth (see also Indigo dye).
The color electric indigo is an approximation of spectrum indigo is the color indigo as it looks reproduced on a computer screen--it is the color between the web color blue and the color violet.
The web color blue violet or bright indigo is a shade of indigo brighter than pigment indigo but not as bright as electic indigo.
The color pigment indigo is equivalent to the web color indigo and is the color indigo that is usually reproduced in pigments and colored pencils. (Electric indigo can be reproduced approximately in pigments, but it requires adding some white pigment to pigment indigo.)
The color of indigo dye is a different color than either spectrum indigo or pigment indigo. A vat full of this dye is a darker color, approximating the web color Midnight Blue.
When referring to the color Indigo it is always necessary to specify which of the four colors all called indigo you are referring to: the color electric indigo, the color blue-violet (bright indigo), the color pigment indigo, or the color indigo dye (they are four entirely separate and distinct colors).
Electric indigo
Spectral indigo is closely approximated by the color electric indigo.
In the psychedelic 1960s, electric indigo color would have been approximated by mixing some fluorescent magenta pigment with a larger amount of fluorescent blue pigment.
Indigo is neither an additive primary color nor a subtractive primary color. By looking at the color band comparison chart below of the three colors blue, indigo, and violet, anyone with normal color vision can easily see that all three of these colors are quite distinct.
Of all the pure chromas, indigo has what chromaticians call the highest value, i.e., indigo is intrinsically the darkest of the colors on the color wheel, just as yellow has the lowest value of all the colors on the color wheel, i.e., yellow is the lightest pure chroma on the color wheel.
Bright indigo (web color blue violet)
At left is displayed the web color blue violet, a color intermediate in brightness between electric indigo and pigment indigo. This color is also called bright indigo.
Pigment indigo (web color indigo)
The color box at right displays the web color Indigo which is equivalent to pigment indigo, i.e., the color indigo as it would be reproduced by artist's paints as opposed to the brighter indigo above (electric indigo) that it is possible to reproduce on a computer screen.
Pigment indigo is the color you would get if you mixed about 55% pigment cyan with about 45% pigment magenta.
Compare the subtractive colors to the additive colors in the two primary color charts in the article on primary colors to see the distinction between electric colors as reproducible from light on a computer screen (additive colors) and the pigment colors reproducible with pigments (subtractive colors);
Pigment indigo (web color indigo) represents the way the color indigo was always reproduced in pigments, paints, or colored pencils in the 1950s. By the 1970s, because of the advent of
psychedelic art, artists became used to brighter pigments, and pigments called "bright indigo" or "bright blue-violet" that are the pigment equivalent of the electric indigo reproduced in the
section above became available in artists pigments and colored pencils. This color sample was taken directly from the indigo dye color swatch in the Wikipedia Indigo dye article. A vat full of
indigo dye would be a much darker color, approximating the web color midnight blue.
Comparison of electric indigo, bright indigo, pigment indigo, indigo dye, and midnight blue
electric indigo (Hex: #6600FF) (RGB: 102, 0, 255) bright indigo (web color blue-violet) (Hex: #8A2BE2) (RGB: 138, 43, 226) pigment indigo (Hex: #4B0082) (RGB: 75, 0, 130) indigo dye (Hex: #1A5798) (RGB: 17, 80, 147) midnight blue (Prussian blue) (Hex: #003366) (RGB: 0, 51, 102)Comparison of blue, indigo, and violet
Note: The spectrum colors can only be approximated on a computer screen due to the color limitations of the color gamut reproducible within the CIE chromaticity diagram.
blue (Hex: #0000FF) (RGB: 0, 0, 255) electric indigo (Hex: #6600FF) (RGB: 102, 0, 255) electric violet (Hex: #8B00FF) (RGB: 139, 0, 255)Indigo in culture
Food
The outer skin of most varieties of eggplant is colored pigment indigo.
User Comments Add a comment…