On the RGB and CMYK color wheel, Azure is defined as the colour halfway between blue and cyan. The colour halfway between blue and cyan on the RGB color wheel has a hex code of 0080FF.[1]
On the RGB color wheel, "azure" (hexadecimal #0080FF) is defined as the color at 210 degrees, i.e., the hue halfway between blue and cyan. In the RGB color model, used to create all the colors on a television or computer screen, azure is created by adding a 50% of green light to a 100% of blue light.
In the X11 color system, which became a model for early web colors, azure is depicted as a pale cyan or white cyan.
The color azure ultimately takes its name from the vivid-blue gemstonelapis lazuli, a metamorphic rock. Lapis is the Latin word for "stone" and lāzulī is the genitive form of the Medieval Latinlāzulum, which is taken from the Arabicلازوردlāzaward[laːzwrd] (listenⓘ), itself from the Persianلاژوردlāžaward, which is the name of the stone in Persian[6] and also of a place where lapis lazuli was mined.[7][8]
The name of the stone came to be associated with its color. The Frenchazur, the Italianazzurro, the Polishlazur, Romanianazur and azuriu, the Portuguese and Spanishazul, Hungarianazúr, and the Catalanatzur, all come from the name and color of lapis lazuli. The dropping of the initial l in Romance languages may be a case of the linguistic phenomenon known as rebracketing, i.e. Romance speakers may have perceived the sound as the initial phoneme of the definitive article in their respective language.
The word was adopted into English from the French, and the first recorded use of it as a color name in English was in 1374 in Geoffrey Chaucer's work Troilus and Criseyde, where he refers to "a broche, gold and asure" (a brooch, gold and azure).[9][10][11]
Some languages, such as Italian, generally consider azure to be a basic colour, separate and distinct from blue. Some sources even go to the point of defining blue as a darker shade of azure.[12]
Azure also describes the color of the mineral azurite, both in its natural form and as a pigment in various paint formulations. In order to preserve its deep color, azurite was ground coarsely. Fine-ground azurite produces a lighter, washed-out color. Traditionally, the pigment was considered unstable in oil paints, and was sometimes isolated from other colors and not mixed.
The use of the term spread through the practice of heraldry, where "azure" represents a blue color in the system of tinctures. In engravings, it is represented as a region of parallel horizontal lines, or by the abbreviation az. or b. In practice, azure has been represented by any number of shades of blue. In later heraldic practice a lighter blue, called bleu celeste ("sky blue"), is sometimes specified.
According to the logic of the RGB color wheel, indigo colors are those colors with hue codes between 255 and 225 (degrees), azure colors are those colors with hue codes between 195 and 225, and cyan colors are those colors with hue codes between 165 and 195. Another way of describing it could be that cyan is a mixture of blue and green light, azure is a mixture of blue and cyan light, and indigo is a mixture of blue and violet light.
All of the colors shown below in the section shades of azure are referenced as having a hue between 195 and 225 degrees, with the exception of the very pale X11 web color azure – RGB (240, 255, 255) – which, with a hue of 180 degrees, is a tone of cyan, but follows the artistic meaning of azure as sky blue.
^On colour plate 33 (page 89) of the 1930 book A Dictionary of Color by Maerz and Paul, the colours on the right side of colour plate 33 from top to bottom represent the most highly saturated colours on the color wheel from cyan to azure, and the colours on the bottom of colour plate 33 from right to left represent the most highly saturated colours on the colour wheel from azure to blue. The colour sample that represents azure is colour sample L12 on Plate 33 on Page 89. See reference to Azure on Page 190 in the index. See also discussion of the color azure, Page 149.