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Blue
Blue is one of the three primary colours in the RYB color model, RYB colour model (traditional colour theory), as well as in the RGB color model, RGB (additive) colour model. It lies between Violet (color), violet and cyan on the optical spectrum, spectrum of visible light. The term ''blue'' generally describes colours perceived by humans observing light with a dominant wavelength that's between approximately 450 and 495 nanometres. Most blues contain a slight mixture of other colours; Azure (color), azure contains some green, while ultramarine contains some violet. The clear daytime sky and the deep sea appear blue because of an optical effect known as Rayleigh scattering#Cause of the blue colour of the sky, Rayleigh scattering. An optical effect called the Tyndall effect explains Eye color#Blue, blue eyes. Distant objects appear more blue because of another optical effect called aerial perspective. Blue has been an important colour in art and decoration since ancient t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primary Colours
Primary colors are colorants or colored lights that can be mixed in varying amounts to produce a gamut of colors. This is the essential method used to create the perception of a broad range of colors in, e.g., electronic displays, color printing, and paintings. Perceptions associated with a given combination of primary colors can be predicted by an appropriate mixing model (e.g., additive, subtractive) that uses the physics of how light interacts with physical media, and ultimately the retina to be able to accurately display the intended colors. The most common color mixing models are the additive primary colors (red, green, blue) and the subtractive primary colors (cyan, magenta, yellow). Red, yellow and blue are also commonly taught as primary colors (usually in the context of subtractive color mixing as opposed to additive color mixing), despite some criticism due to its lack of scientific basis. Primary colors can also be conceptual (not necessarily real), either as addi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blue And White Porcelain
"Blue and white pottery" () covers a wide range of white pottery and porcelain decorated underglaze, under the glaze with a blue pigment, generally cobalt(II) oxide, cobalt oxide. The decoration was commonly applied by hand, originally by brush painting, but nowadays by stencilling or by transfer-printing, though other methods of application have also been used. The cobalt pigment is one of the very few that can withstand the highest firing temperatures that are required, in particular for porcelain, which partly accounts for its long-lasting popularity. Historically, many other colours required overglaze decoration and then a second firing at a lower temperature to fix that. The origin of the blue glazes is thought to lie in Iraq, when craftsmen in Basra sought to imitate imported white Chinese stoneware with their own tin-glazed, white pottery and added decorative motifs in blue glazes. Such Abbasid Caliphate, Abbasid-era pieces have been found in present-day Iraq dating to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eye Color
Eye color is a polygene, polygenic phenotypic trait determined by two factors: the pigmentation of the eye's Iris (anatomy), iris and the frequency-dependence of the scattering of light by the Turbidity, turbid medium in the Stroma of iris, stroma of the iris. In humans, the pigmentation of the Iris (anatomy), iris varies from light brown to black, depending on the concentration of melanin in the iris pigment epithelium (located on the back of the iris), the melanin content within the iris stroma (located at the front of the iris), and the cellular density of the stroma. The appearance of blue, green, and hazel eyes results from the Tyndall effect, Tyndall scattering of light in the stroma, a phenomenon similar to Rayleigh scattering which accounts for the blue sky. Neither blue nor green pigments are present in the human iris or vitreous humour. This is an example of structural color, which depends on the lighting conditions, especially for lighter-colored eyes. The brightly c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultramarine
Ultramarine is a deep blue pigment which was originally made by grinding lapis lazuli into a powder. Its lengthy grinding and washing process makes the natural pigment quite valuable—roughly ten times more expensive than the stone it comes from and as expensive as gold. The name ultramarine comes from the Latin word . The word means 'beyond the sea', as the pigment was imported by Italian traders during the 14th and 15th centuries from mines in Afghanistan. Much of the expansion of ultramarine can be attributed to Venice which historically was the port of entry for lapis lazuli in Europe. Ultramarine was the finest and most expensive blue used by Renaissance painters. It was often used for the robes of the Virgin Mary and symbolized holiness and humility. It remained an extremely expensive pigment until a synthetic ultramarine was invented in 1826. Ultramarine is a permanent pigment when under ideal preservation conditions. Otherwise, it is susceptible to discoloration a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cobalt Blue
Cobalt blue is a blue pigment made by sintering cobalt(II) oxide with aluminium(III) oxide (alumina) at 1200 °C. Chemically, cobalt blue pigment is cobalt(II) oxide-aluminium oxide, or cobalt(II) aluminate, CoAl2O4. Cobalt blue is lighter and less intense than the (iron-cyanide based) pigment Prussian blue. It is extremely stable, and has historically been used as a coloring agent in ceramics (especially Chinese porcelain), jewelry, and paint. Transparent glasses are tinted with the silica-based cobalt pigment "smalt". Historical uses and production Ores containing cobalt have been used since antiquity as pigments to give a blue color to porcelain and glass. Cobalt blue in impure forms had long been used in Chinese porcelain. In 1742, Swedish chemist Georg Brandt showed that the blue color was due to a previously unidentified metal, cobalt. The first recorded use of ''cobalt blue'' as a color name in English was in 1777. It was independently discovered as an alumina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyan
Cyan () is the color between blue and green on the visible spectrum of light. It is evoked by light with a predominant wavelength between 500 and 520 nm, between the wavelengths of green and blue. In the subtractive color system, or CMYK color model, which can be overlaid to produce all colors in paint and color printing, cyan is one of the primary colors, along with magenta and yellow. In the additive color system, or RGB color model, used to create all the colors on a computer or television display, cyan is made by mixing equal amounts of green and blue light. Cyan is the complement of red; it can be made by the removal of red from white. Mixing red light and cyan light at the right intensity will make white light. It is commonly seen on a bright, sunny day in the sky. Shades and variations Different shades of cyan can vary in terms of hue, chroma (also known as saturation, intensity, or colorfulness), or lightness (or value, tone, or brightness), or any combinat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indigo Dye
Indigo dye is an organic compound with a distinctive indigo, blue color. Indigo is a natural dye obtained from the leaves of some plants of the Indigofera#Uses, ''Indigofera'' genus, in particular ''Indigofera tinctoria''. Dye-bearing ''Indigofera'' plants were once common throughout the world. It is now produced via chemical routes. Blue colorants are rare. Since indigo is insoluble, it is also referred to as a pigment (C.I. Pigment Blue 66, C.I.). Most indigo dye produced today is chemical synthesis, synthetic, constituting around 80,000 tonnes each year, as of 2023. It is most commonly associated with the production of denim cloth and jeans, blue jeans, where its properties allow for effects such as stone washing and stone washing#Acid-washed jeans, acid washing to be applied quickly. Uses The primary use for indigo is as a dye for cotton yarn, mainly used in the production of denim cloth suitable for blue jeans; on average, a pair of blue jeans requires to of dye. Smal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azure (color)
Azure ( , ) is the color between cyan and blue on the visible spectrum, spectrum of visible light. It is often described as sky blue, the color of the sky on a clear day. On the :File:RGB color wheel.svg, RGB color wheel, "azure" (Web colors#Hex triplet, hexadecimal #0080FF) is defined as the color at 210 degrees, i.e., the hue halfway between Shades of blue#Blue (RGB) (X11 blue), 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 names, X11 color system, which became a model for early web colors, azure is depicted as a pale cyan or white cyan. Etymology and history The color azure ultimately takes its name from the vivid-blue gemstone lapis lazuli, a metamorphic rock. ' is the Latin word for "stone" and ' is the genitive form of the Medieval Latin ', which is taken from the Arabic ''lāzaward'' (), itself from the Persian lan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RGB Color Model
The RGB color model is an additive color, additive color model in which the red, green, and blue primary colors of light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additive primary colors, red, green, and blue. The main purpose of the RGB color model is for the sensing, representation, and display of images in electronic systems, such as televisions and computers, though it has also been used in conventional photography and Light-emitting diode#RGB systems, colored lighting. Before the electronic age, the RGB color model already had a solid theory behind it, based in Trichromacy, human perception of colors. RGB is a ''device-dependent'' color model: different devices detect or reproduce a given RGB value differently, since the color elements (such as phosphors or dyes) and their response to the individual red, green, and blue levels vary from manufacturer to manufacturer, or even in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Violet (color)
Violet is the color of light at the short wavelength end of the visible spectrum. It is one of the seven colors that Isaac Newton labeled when dividing the spectrum of visible light in 1672. Violet light has a wavelength between approximately 380 and 450 nanometers. The color's name is derived from the ''Viola'' genus of flowers. In the RGB color model used in computer and television screens, violet is produced by mixing red and blue light, with more blue than red. In the RYB color model historically used by painters, violet is created with a combination of red and blue pigments and is located between blue and purple on the color wheel. In the CMYK color model used in printing, violet is created with a combination of magenta and cyan pigments, with more magenta than cyan. On the RGB/ CMY( K) color wheel, violet is located between blue and magenta. Violet is closely associated with purple. In optics, violet is a spectral color (referring to the color of different single wav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rayleigh Scattering
Rayleigh scattering ( ) is the scattering or deflection of light, or other electromagnetic radiation, by particles with a size much smaller than the wavelength of the radiation. For light frequencies well below the resonance frequency of the scattering medium (normal dispersion relation, dispersion regime), the amount of scattering is inversely proportional to the fourth power of the wavelength (e.g., a blue color is scattered much more than a red color as light propagates through air). The phenomenon is named after the 19th-century British physicist Lord Rayleigh (John William Strutt). Rayleigh scattering results from the electric polarizability of the particles. The oscillating electric field of a light wave acts on the charges within a particle, causing them to move at the same frequency. The particle, therefore, becomes a small radiating dipole whose radiation we see as scattered light. The particles may be individual atoms or molecules; it can occur when light travels throu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RYB Color Model
RYB (an abbreviation of red–yellow–blue) is a subtractive color model used in art and applied design in which red, yellow, and blue pigments are considered primary colors. Under traditional color theory, this set of primary colors was advocated by Moses Harris, Michel Eugène Chevreul, Johannes Itten and Josef Albers, and applied by countless artists and designers. The RYB color model underpinned the color curriculum of the Bauhaus, Ulm School of Design and numerous art and design schools that were influenced by the Bauhaus, including the IIT Institute of Design (founded as the New Bauhaus), Black Mountain College, Design Department Yale University, the Shillito Design School, Sydney, and Parsons School of Design, New York. In this context, the term ''primary color'' refers to three exemplar colors (red, yellow, and blue) as opposed to specific pigments. As illustrated, in the RYB color model, red, yellow, and blue are intermixed to create secondary color segments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
