Indigo

n. dark violet-blue color

adj. having a dark violet-blue color

Indigo is the color on the electromagnetic spectrum between about 450 and 420 nm in wavelength, placing it between blue and violet. Color scientists do not usually recognize indigo as a significant color category, and generally classify wavelengths shorter than about 450 nm as violet.Indigo and violet are different from purple, which cannot be seen on the electromagnetic spectrum but can be achieved by mixing blue light with red light.One can see spectral indigo by looking at the reflection of a fluorescent tube in a non-recordable compact disc. This works because the CD functions as a diffraction grating, and a fluorescent lamp generally has a peak at 435.833 nm (from  mercury), as is visible on the fluorescent lamp spectrum.
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IndiGo Airlines is a private domestic low-cost airline based in Gurgaon, India. It operates domestic services linking 14 destinations. Its main base is Indira Gandhi International Airport, Delhi.
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Indigo Airlines is generally regarded as the world's first business jet airline. It was founded in 1997 by aviation veteran and University of Chicago graduate Matt Andersson; business executive and Embry-Riddle Aeronautical University alumnus John N. Fenton and McKinsey consultant and MIT PhD. Tom Svrcek.
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Noun
1. a blue dye obtained from plants or made synthetically
(synonym) anil, indigotin
(hypernym) dye, dyestuff
2. deciduous subshrub of southeastern Asia having pinnate leaves and clusters of red or purple flowers; a source of indigo dye
(synonym) indigo plant, Indigofera tinctoria
(hypernym) shrub, bush
(hyponym) anil, Indigofera suffruticosa, Indigofera anil
(member-holonym) Indigofera, genus Indigofera
3. a blue-violet color
(hypernym) violet, reddish blue

n. indigo, dark violet-blue color

adj. indigo

n. indigo, dark violet-blue color