Deep sky blue
A web colour halfway between azure and cyan on the colour wheel
Deep sky blue is a bright, clear blue-green shade that sits between azure and cyan on the colour wheel. It became an official web colour in the late 1980s and shares its colour coordinates with Capri, a name first used in English in 1920.
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- Halfway between azure and cyan on the colour wheel
- A standard web colour since the late 1980s
- Identical in value to the colour Capri
- Defined by digital RGB values, not by pigment
What colour is Deep sky blue?
Deep sky blue is a vivid blue-green colour, brighter and more intense than standard sky blue. It sits exactly halfway between azure and cyan on the RGB or HSV colour wheel, making it distinct from both. Its appearance is clear and saturated, similar to the colour of a clear sky at its deepest, but with a touch more green than pure blue.
Where does Deep sky blue come from?
The name 'deep sky blue' was introduced with the X11 colour names, a set of standards for computer displays, between 1985 and 1989. The colour's coordinates are identical to those of Capri, which appeared as a colour name in English in 1920. Deep sky blue's definition is based on its position on the colour wheel, not on a natural pigment or dye.
How Deep sky blue is defined
Deep sky blue is a digital colour, defined by its RGB values for use on screens. It does not come from a physical pigment or dye, but is produced by mixing light in precise amounts: it is halfway between azure and cyan in the RGB colour model.
Where Deep sky blue is used
This colour is mainly used in digital contexts, such as web design and computer graphics, where precise colour standards are needed. Its clear, bright appearance makes it useful for highlighting or creating a sense of clarity and freshness on screens.
Turquoise around the world
What the turquoise and cyan family means from country to country.
The old colour word qing covers green, blue and the shades between. In the five-element system it belongs to wood, the east and spring.
Nature and renewalCalmSource: Blue–green distinction in languageTurquoise, firuzeh in Persian, has been mined near Nishapur for thousands of years. It is worn against the evil eye, and its colour covers the domes of mosques in Isfahan.
Protection and healingSacred and holyAweSource: TurquoiseIn the image of Our Lady of Guadalupe, Mary wears a blue-green cloak covered in stars. Turquoise was precious to the Aztecs, who used it in mosaic masks.
Sacred and holyAweSource: Our Lady of GuadalupeThe English word turquoise comes from the French for Turkish, because the stone reached Europe through Ottoman lands. Tiles from Iznik made the colour a mark of Ottoman mosques.
Royalty and powerSource: TurquoiseThe mosques and tombs of Samarkand are faced with turquoise and deep blue tiles. The three great madrasas of the Registan square and their ribbed turquoise domes are the best known.
Sacred and holyAweSource: RegistanShades and relatives of Deep sky blue
Deep sky blue is closely related to Capri, as they share the same colour coordinates. It is also part of a family of blue-green shades, sitting between azure (a more blue shade) and cyan (a more greenish blue).
Colours that go with Deep sky blue
Harmonies are worked out from the value #00BFFF. Contrast ratios follow the WCAG 2 formula.
Questions people ask about Deep sky blue
What colour is deep sky blue?
Deep sky blue is a bright, clear blue-green shade, sitting halfway between azure and cyan on the colour wheel.
Where does the name deep sky blue come from?
The name was introduced with the X11 colour standards for computer displays between 1985 and 1989.
Is deep sky blue the same as Capri?
Yes, deep sky blue and Capri have identical colour coordinates in digital colour systems.
How is deep sky blue made?
It is a digital colour, created by mixing light in specific RGB values, not by using any pigment or dye.
Good reading and sources
The facts on this page come from the Wikipedia article "Sky blue" (the section "Deep sky blue"), written by its contributors and used under the CC BY-SA 4.0 licence. Rang rewrote the text in its own words, with AI assistance, and compares every page with the article to make sure no passage is copied. It may be reused under the same CC BY-SA 4.0 licence with a link back.
It may contain mistakes. The swatch is an approximation: named colours are not fixed standards, and every screen shows them a little differently. If something is wrong, tell us. Last refreshed 2026-10-03.
More of the turquoise and cyan family
All of turquoise and cyan
#00FFFF
Cyan
A blue-green colour found between blue and green on the spectrum and key in printingBasic colour
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Turquoise
A blue-green colour named after a prized mineral long used for gems and decorationNamed shade · 🇮🇷 Iran +5
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Teal
A dark cyan named after the Eurasian teal bird’s blue-green head stripeNamed shade
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Haint blue
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Aqua
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Olo
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Blue-green
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Tiffany Blue
A light blue-green shade trademarked by Tiffany & Co. for its boxes and brandingNamed shade