Sky blue refers to a collection of shades comparable to that of a clear daytime sky.[1] Typically it is a shade of cyan or light teal, though some iterations are closer to light blue. The term (as "sky blew") is attested from 1681.[1] A 1585 translation of Nicolas de Nicolay's 1576 Les navigations, peregrinations et voyages faicts en la Turquie includes "the tulbant [turban] of the merchant must be skie coloured".[2]
Celeste (Spanish:[θeˈleste,se-], Italian:[tʃeˈlɛste], English: /sɪˈlɛst/) is the colloquial name for the pale turquoiseblue colour. The same word, meaning "of the sky", is used in Spanish, Portuguese and Italian for the colour. Etymologically, it is derived by Latin term caelestis, that means del cielo in Italian.[3] There are two "conventional" colours denominated celeste, according to the color models. One is the pure Celeste, (HEX#B2FFFF; RGB 178,255,255)[4] which may be referred as the "true" celeste as it is traditionally or officially understood; in English, it may also be referred to as Italian sky blue (blu cielo italiano)[5][6][7][8][9] and Bianchi Green, referring to Bianchi, the famous Italian company for bikes, the first in the history of vehicles, whose colour is characteristic.[10][11] The Japanese equivalent is known as sora iro or mizuiro, referring to the colour of the sky or its reflection on the sea.[12] The other one is also another conventional celeste (HEX #99cbff and RGB 153,203,255) containing 100% of blue,[13][14] associated to a more generic color of the sky and remembering a type of light zenithal blue and the next sky blue gradations.
Pure Celeste between Spadafora and Torregrotta, Sicily in September; the color of the ideal sky is shown with a perfectly or near-perfectly weather, especially close to the horizon, where the cyan is more evident.
Celeste, that is, the pure Celeste strictly speaking (HEX #B2FFFF; RGB 178,255,255)[4] from here on (and which can be thought as the "true" or "conventional" celeste), is a gradation of the cyan[15][16][17] and a cold color.[18] It is the colour of the sky with optimal visibility, when it is clear, perfectly or near-perfectly cloudless and sunny with an optimal quantity of humidity, absence or optimal quantity of atmospheric dust, aerosol/particulates with a good or at least moderate AIQ (Air Quality Index),[19][20] absence of mist, haze, resulting in a good diffusion of light blue without saturation, which causes the prevalence of the white or of the warm colours of sunrise and sunset; in these excellent conditions, it is possible to see Celeste and its variations[21][22][23][24] perpendicularly to the sun, toward the horizon, where the sunlight is maximum as the sky is directly illuminated, and these shades merge with the golden light of solar rays and the white of the horizon, both in the morning and afternoon, or even across the entire region between the star and the horizon, when the star is high, relatively next to solar or true noon.[25] In particular, in the warm seasons, with the inclination of a hemisphere with respect to the sun,[26][27][28][29] there are simultaneously the optimization of sunlight, daylight hours, and so the pure celeste might be visible in the entire region between the horizon and sun both in the morning and afternoon; generally, the higher the sun is during the day and the year, the less visible celeste and variations will be. In particular, in the morning across the sun and the horizon in the early hours with the rising of the star, sometimes even until noon, until they are reduced to a few stripes on the horizon, where the cyan is more intense. In the afternoon, it is the opposite and the pure celeste and similar gradations could be widely visible between the sun and horizon when the star is high, but starting to go down, that is especially in the early afternoon hours. Instead, in the cold season, with a low sun and sunlight, the pure celeste may be visible only at the horizon, where the cyan is more intense for the maximum light, but is more difficult because of the major weather instability. In anyway, since sunlight is strongest at the horizon, that is where the pure celeste is more evident, producing the tonalities of the cyan, very close to the white.
Pure Celeste between Spadafora and Torregrotta, Sicily, with a perfectly clear, serene and sunny weather in September. Note that the pure celeste is more evident close to the horizon, where the cyan is more intense.
Alternatively, other variants, like Celeste polvere,Pallido and Velato, are visible towards the horizon when the sun is near to the zenith, always with discrete or good conditions of visibility. In the afternoon, always with good conditions, these three type of celeste, together with softer and less bright shades of celeste, are visible at straight angle from north to south, until around sunset.
In reality, it can be difficult to observe the pure celeste, being the color of a clear day with optimal meteorological factories; other shades of blue are often visible in the sky, as Light Sky Blue and similar gradations, among which the other conventional celeste,[13] similar to the light blue sky colours rather than the pure celeste. One scientific explanation needs to be made: the sun emits light across the entire electromagnetic spectrum[30][31] and so celeste, which is very close to the white with a RGB of 178,255,255, is very luminous, and so visible in the direction of the sun because it is there the maximum quantity of solar light, especially towards the horizon, even if human eyes can only perceive the visible light. Here because celeste and variations are easier to be visible in the warm seasons because of the inclination of a hemisphere with respect to the sun,[26][27][28][29]spring and especially summer, with the optimization of solar light, hours of daylight and meteorological factors.
Pure celeste at the horizon of Messina, Sicily, in February; in this part of the year, with a relatively low sun, the pure celeste is shown only at the horizon and around noon.
Being the gradation of near-perfectly sunny and clear sky, the color of an ideal sky, it is difficult to see pure celeste, especially during the coldest or most unstable seasons; instead, generically the sky shows the color of the other conventional celeste with 100% of blue, recalling a light zenithal blue and the next other types of sky blue;[13][14] this is not surprising due to the best diffusion of the blue because of the Raylegh scattering.
Bleu celeste ("sky blue") is a rarely occurring tincture in heraldry (not being one of the seven main colours or metals or the three "staynard colours"). This tincture is sometimes also called ciel or simply celeste. It is depicted in a lighter shade than the range of shades of the more traditional tincture azure, which is the standard blue used in heraldry.[32]
Gradations
The Italian Wikipedia cites Il dizionario dei colori: nomi e valori in quadricromia by S.Fantetti and C.Petracchi and describes multiple variants of celeste as shown below, plus details as defined in the infobox above.[33]
colour
name
C
M
Y
K
R
G
B
HEX
celeste (sky blue, heavenly blue, italian sky blue, bianchi green)
Displayed at right is the colour medium sky blue. This is the colour that is called sky blue in Crayola crayons. This colour was formulated by Crayola in 1958.
"Sky blue" appears in the 32, 48, 64, 96 and 120 packs of crayons.
At right is displayed the colour French sky blue, which is the tone of sky blue that is called sky blue (bleu ciel) in the Pourpre.com colour list, a colour list widely popular in France.
Spanish sky blue is the colour that is called celeste (the Spanish word for "sky blue") in the Guía de coloraciones (Guide to colourations) by Rosa Gallego and Juan Carlos Sanz, a colour dictionary published in 2005 that is widely popular in the Hispanophone realm.
Australia: Sky blue is the main colour of the Australian rugby league team, New South Wales Blues, as it is the official colour of the state they represent.
Sweden: Football club Malmö FF, the club with the most Swedish championships, adopted sky blue shirts in 1920, which have been used for more than a century.
United Kingdom: Two professional football clubs in England traditionally wear sky blue shirts. Manchester City adopted sky blue as the main colour of their home jersey in 1894 and have used that ever since then.[38]Coventry City also have had sky blue as the primary colour since the 1960s.[39]
^Naturally, the apparent height of the star from the Earth changes in the year with the four seasons, depending by the axial tilt of the planet respect to the Sun, so this is a general rule. Generically, what is said here for Celeste is valid for the regions between the equator and the two polar circles, including the temperate zones and subtropics. In these zones, the sun remains high enough throughout the year, especially in the warm seasons (spring, summer). Naturally, the closer you are to the equator the higher it will appear.
^Scott-Giles, C. W. (1958). Boutell's Heraldry (rev. ed.). London & New York: Frederick Warne & Co.
^S.Fantetti e C.Petracchi (2001). Il dizionario dei colori: nomi e valori in quadricromia. Zanichelli. ISBN8808079953.
^Maerz and Paul A Dictionary of Color New York:1930 McGraw-Hill Color Sample of Capri: Page 93 Plate 35 Color Sample L7; The color Capri is shown as lying halfway between Cyan and Azure.
^Maerz and Paul A Dictionary of Color New York:1930 McGraw-Hill Page 191
^Gallego, Rosa; Sanz, Juan Carlos (2005). Guía de coloraciones (Gallego, Rosa; Sanz, Juan Carlos (2005). Guide to Colorations) Madrid: H. Blume. ISBN84-89840-31-8
^ ab"PANTONE 14-4318 TPX Sky Blue". Pantone. Retrieved 19 December 2022. Displays a sky blue patch; exact rendering will depend upon the computer display used.
