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Shades Of Black
Shades of black are colors that differ only slightly from pure black. These colors have a low lightness. From a photometric point of view, a color which differs slightly from black always has low relative luminance. Variations of black include what are commonly termed off-black colors, which may be considered part of a neutral color scheme, usually in interior design as a part of a background for brighter colors. Black and dark gray colors are powerful accent colors that suggest weight, dignity, formality, and solemnity. In color theory, a '' shade'' is a pure color mixed with black. It decreases its lightness while nearly conserving its chromaticity. Strictly speaking, a "shade of black" is always a pure black itself and a "tint of black" would be a neutral gray. Unlike these, many off-black colors possess a hue and a colorfulness (also called saturation). Colors often considered "shades of black" include ''onyx'', ''black olive'', ''charcoal'', and ''jet''; these colors an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Darkness
Darkness, the direct opposite of lightness, is defined as a lack of illumination, an absence of visible light, or a surface that absorbs light, such as black or brown. Human vision is unable to distinguish colors in conditions of very low luminance. This is because the hue sensitive photoreceptor cells on the retina are inactive when light levels are insufficient, in the range of visual perception referred to as scotopic vision. The emotional response to darkness has generated metaphorical usages of the term in many cultures, often used to describe an unhappy or foreboding feeling. Referring to a time of day, complete darkness occurs when the Sun is more than 18° below the horizon, without the effects of twilight on the night sky. Scientific Perception The perception of darkness differs from the mere absence of light due to the effects of after images on perception. In perceiving, the eye is active, and the part of the retina that is unstimulated produces a compleme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cone Cells
Cone cells, or cones, are photoreceptor cells in the retinas of vertebrate eyes including the human eye. They respond differently to light of different wavelengths, and the combination of their responses is responsible for color vision. Cones function best in relatively bright light, called the photopic region, as opposed to rod cells, which work better in dim light, or the scotopic region. Cone cells are densely packed in the fovea centralis, a 0.3 mm diameter rod-free area with very thin, densely packed cones which quickly reduce in number towards the periphery of the retina. Conversely, they are absent from the optic disc, contributing to the blind spot. There are about six to seven million cones in a human eye (vs ~92 million rods), with the highest concentration being towards the macula. Cones are less sensitive to light than the rod cells in the retina (which support vision at low light levels), but allow the perception of color. They are also able to perceive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Oxide
Iron oxides are chemical compounds composed of iron and oxygen. Several iron oxides are recognized. All are black magnetic solids. Often they are non-stoichiometric. Oxyhydroxides are a related class of compounds, perhaps the best known of which is rust. Iron oxides and oxyhydroxides are widespread in nature and play an important role in many geological and biological processes. They are used as iron ores, pigments, catalysts, and in thermite, and occur in hemoglobin. Iron oxides are inexpensive and durable pigments in paints, coatings and colored concretes. Colors commonly available are in the "earthy" end of the yellow/orange/red/brown/black range. When used as a food coloring, it has E number E172. Stoichiometries Iron oxides feature as ferrous ( Fe(II)) or ferric (Fe(III)) or both. They adopt octahedral or tetrahedral coordination geometry. Only a few oxides are significant at the earth's surface, particularly wüstite, magnetite, and hematite. * Oxides of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slate
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. It is the finest grained foliated metamorphic rock. Foliation may not correspond to the original sedimentary layering, but instead is in planes perpendicular to the direction of metamorphic compression. The foliation in slate is called " slaty cleavage". It is caused by strong compression causing fine grained clay flakes to regrow in planes perpendicular to the compression. When expertly "cut" by striking parallel to the foliation, with a specialized tool in the quarry, many slates will display a property called fissility, forming smooth flat sheets of stone which have long been used for roofing, floor tiles, and other purposes. Slate is frequently grey in color, especially when seen, en masse, covering roofs. However, slate occurs in a variety of colors even from a single locality; for e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ebony
Ebony is a dense black/brown hardwood, coming from several species in the genus '' Diospyros'', which also contains the persimmons. Unlike most woods, ebony is dense enough to sink in water. It is finely textured and has a mirror finish when polished, making it valuable as an ornamental wood. The word ''ebony'' comes from the Ancient Egyptian ', through the Ancient Greek ('), into Latin and Middle English. Species Species of ebony include ''Diospyros ebenum'' (Ceylon ebony), native to southern India and Sri Lanka; '' D. crassiflora'' (Gabon ebony), native to western Africa; and '' D. celebica'' (Sulawesi ebony), native to Indonesia and prized for its luxuriant, multi-colored wood grain. Mauritius ebony, '' D. tessellaria'', was largely exploited by the Dutch in the 17th century. Some species in the genus yield an ebony with similar physical properties, but striped rather than the even black of ''D. ebenum''. Uses Ebony has a long history of use, and carved pieces hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pantone
Pantone LLC (stylized as PANTONE) is a limited liability company headquartered in Carlstadt, New Jersey. The company is best known for its Pantone Matching System (PMS), a proprietary color space used in a variety of industries, notably graphic design, fashion design, product design, printing and manufacturing and supporting the management of color from design to production, in physical and digital formats, among coated and uncoated materials, cotton, polyester, nylon and plastics. X-Rite, a supplier of color measurement instruments and software, purchased Pantone for US$180 million in October 2007, and was itself acquired by Danaher Corporation in 2012. Overview Pantone began in New Jersey in the 1950s as the commercial printing company of brothers Mervin and Jesse Levine, M & J Levine Advertising. In 1956, its founders, both advertising executives, hired recent Hofstra University graduate Lawrence Herbert as a part-time employee. Herbert used his chemistry knowledge to s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blue
Blue is one of the three primary colours in the RYB colour model (traditional colour theory), as well as in the RGB (additive) colour model. It lies between violet and cyan on the spectrum of visible light. The eye perceives blue when observing light with a dominant wavelength between approximately 450 and 495 nanometres. Most blues contain a slight mixture of other colours; 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. An optical effect called Tyndall effect explains 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 times. The semi-precious stone lapis lazuli was used in ancient Egypt for jewellery and ornament and later, in the Renaissance, to make the pigment ultramarine, the most expensive of all pigments. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gray
Grey (more common in British English) or gray (more common in American English) is an intermediate color between black and white. It is a neutral or achromatic color, meaning literally that it is "without color", because it can be composed of black and white. It is the color of a cloud-covered sky, of ash and of lead. The first recorded use of ''grey'' as a color name in the English language was in 700 CE.Maerz and Paul ''A Dictionary of Color'' New York:1930 McGraw-Hill Page 196 ''Grey'' is the dominant spelling in European and Commonwealth English, while ''gray'' has been the preferred spelling in American English; both spellings are valid in both varieties of English. In Europe and North America, surveys show that grey is the color most commonly associated with neutrality, conformity, boredom, uncertainty, old age, indifference, and modesty. Only one percent of respondents chose it as their favorite color. Etymology ''Grey'' comes from the Middle English ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X11 Color Names
In computing, on the X Window System, X11 color names are represented in a simple text file, which maps certain strings to RGB color values. It was traditionally shipped with every X11 installation, hence the name, and is usually located in ''<X11root>''/lib/X11/rgb.txt. The web colors list is descended from it but differs for certain color names. Color names are not standardized by Xlib or the X11 protocol. The list does not show continuity either in selected color values or in color names, and some color triplets have multiple names. Despite this, graphic designers and others got used to them, making it practically impossible to introduce a different list. In earlier releases of X11 (prior to the introduction of Xcms), server implementors were encouraged to modify the RGB values in the reference color database to account for gamma correction. As of X.Org Release 7.4 rgb.txt is no longer included in the roll up release, and the list is built directly into the server. The op ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vantablack
Vantablack is a brand name for a class of super-black coatings with total hemispherical reflectances (THR) below 1.5% in the visible spectrum. The coatings were invented by Ben Jensen, who first publicly unveiled them in July 2014, and commercialised by the scientific team from Surrey NanoSystems. The original Vantablack coating was grown from a chemical vapour deposition process (CVD) and is claimed to be the "world's darkest material", absorbing up to 99.965% of visible light perpendicular to the material at 663 nm. The coatings are unique in that they are not only super-black but that they retain uniform light absorption from almost all viewing angles. Original CVD Vantablack is no longer manufactured for commercial applications as it has been superseded by Vantablack spray coatings that offer similar optical performance in key parts of the electromagnetic spectrum. The name is a combination of the acronym ''VANTA'' ( vertically aligned nanotube arrays) and the color ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Super Black
Super black is a surface treatment developed at the National Physical Laboratory (NPL) in the United Kingdom. It absorbs approximately 99.6% of visible light at normal incidence, while conventional black paint absorbs about 97.5%. At other angles of incidence, super black is even more effective: at an angle of 45°, it absorbs 99.9% of light. Technology The technology to create super black involves chemically etching a nickel-phosphorus alloy. Applications of super black are in specialist optical instruments for reducing unwanted reflections. The disadvantage of this material is its low optical thickness, as it is a surface treatment. As a result, infrared light of a wavelength longer than a few micrometers penetrates through the dark layer and has much higher reflectivity. The reported spectral dependence increases from about 1% at 3 µm to 50% at 20 µm. In 2009, a competitor to the super black material, Vantablack, was developed based on carbon nanotubes. It has a re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
