Shades of black
Shades of black are colors that differ only slightly from pure black. These colors have a low lightness, from photometric point of view, a color which differs slightly from black always has low relative luminance. Black and dark colors are powerful accent colors that suggest weight, formality. In color theory, a shade is a pure color mixed with black and it decreases its lightness while nearly conserving its chromaticity. Strictly speaking, a “shade of black” is always a pure black itself, unlike these, many off-black colors possess a hue and a colorfulness. Colors often considered shades of black onyx, black olive and jet. A black visual stimulation will be void of hue and grayness, Black is the darkest possible color. A black body is a physical body that absorbs all incident electromagnetic radiation. To the human eye it seems black, midnight blue is a dark shade of blue named for its resemblance to the identifiably blue color of a moonlit night sky on or near the night of a full moon. This is the X11 web color midnight blue and this color was originally called midnight.
The first recorded use of midnight as a name in English was in 1915. At right is displayed the web color dim gray and this color is a dark tone of gray. The color name dim gray first came into use in 1987, after the invention of the World Wide Web in 1991, these colors became known as the X11 web colors. Displayed at right is the color ebony and this color is a representation of the color of the wood ebony, a tropical hardwood widely used to make fine furniture, notably for French kings. The first use of ebony as a name in English was in 1590. The color displayed at left matches the color called taupe referenced below in the 1930 book A Dictionary of Color. However, the word taupe is currently used to refer to lighter shades of taupe. The first use of taupe as a name in English was in the early 19th century
Indigo is a deep and rich color close to the color wheel blue, as well as to some variants of ultramarine. The color indigo is named after the indigo dye derived from the plant Indigofera tinctoria, the first known recorded use of indigo as a color name in English was in 1289. Species of Indigofera were cultivated in Peru, East Asia, the earliest direct evidence for the use of indigo dates to around 4000 BCE and comes from Huaca Prieta, in contemporary Peru. Pliny mentions India as the source of the dye, imported in small quantities via the Silk Road, the Greek term for the dye was Ἰνδικὸν φάρμακον, adopted to Latin as indicum and via Portuguese gave rise to the modern word indigo. El Salvador has lately been the biggest producer of indigo, Indigo was actually a plant that got its name because it came from the Indus Valley, discovered some 5,000 years ago, where it was called nila, meaning dark blue. And by the 7th Century BC, people starting using the plant as a dye — the Mesopotamians were even carving out recipes for making indigo dye onto clay tablets for record-keeping.
By 1289, knowledge of the dye made its way to Europe, but it wasn’t until 1640 when demand started to pick up for indigo. Spanish explorers discovered an American species of Indigo and began to cultivate the product in Guatemala, the English and French subsequently began to encourage indigo cultivation in their colonies in the West Indies. Indigo dye could be made from two different types of plants — the indigo plant, which produced the best results, the British were producing indigo with woad, a plant that yielded a lesser quality dye, but a plant they could grow. They even tried to hold their monopoly on indigo dye by managing to ban the indigo plant for years, but eventually the British began to focus on tea and other crops — and meanwhile, the French started to get their fair share of the market. The French had gone to war with Britain, so the British could hardly rely on the French for this precious blue dye, the British had to turn to their colonies in America. It was Eliza Lucas from South Carolina who figured out how to grow the indigo plant, the same indigo dye is contained in the woad plant, Isatis tinctoria, for a long time the main source of blue dye in Europe.
Woad was replaced by true indigo as trade routes opened up, the Early Modern English word indigo referred to the dye, and not to the color itself, and indigo is not traditionally part of the basic color-naming system. Modern sources place indigo in the spectrum between 420 and 450 nanometers, which lies on the side of color wheel blue. However, the correspondence of this definition with colors of actual indigo dyes is disputed, isaac Newton introduced indigo as one of the seven base colors of his work. In a pivotal experiment in the history of optics, the young Newton shone a narrow beam of sunlight through a prism to produce a band of colors on the wall. He linked the seven prismatic colors to the seven notes of a major scale, as shown in his color wheel, with orange. Indigo is therefore counted as one of the colors of the rainbow
Shades of yellow
Varieties of the color yellow may differ in hue, chroma or lightness, or in two or three of these qualities. Variations in value are called tints and shades, a tint being a yellow or other hue mixed with white, a large selection of these various colors is shown below. Displayed at right is the web color light yellow, displayed at right is the web color cream, a pale tint of yellow. Displayed at right is the web color lemon chiffon Lemon chiffon is a color that is reminiscent of the color of lemon chiffon cake. The color box at right shows the most intense yellow representable in 8-bit RGB color model and this color is called color wheel yellow. It is at precisely 60 degrees on the HSV color wheel, process yellow, known as canary yellow, is one of the three colors typically used as subtractive primary colors, along with magenta and cyan. Process yellow is not an RGB color, and in the CMYK color model there is no fixed conversion from CMYK primaries to RGB, different formulations are used for printers ink, so there can be variations in the printed color that is pure yellow ink.
The first recorded use of yellow as a color name in English was in 1789. The color defined as yellow in the NCS or Natural Color System is shown at right, the Natural Color System is a color system based on the four unique hues or psychological primary colors red, yellow and blue. The NCS is based on the opponent process theory of vision, the “Natural Color System” is widely used in Scandinavia. The color defined as yellow in the Munsell color system is shown at right, in order for all the colors to be spaced uniformly, it was found necessary to use a color wheel with five primary colors—red, green and purple. The Munsell colors displayed are only approximate as they have adjusted to fit into the sRGB gamut. The color that is called yellow in Pantone is displayed at right, the source of this color is the Pantone Textile Paper eXtended color list, color #C, EC, M, PC, U, or CP—Yellow. The color that is called yellow in Crayola crayons is displayed at right, Yellow was one of the original Crayola colors formulated in 1903.
The color unmellow yellow is shown at right, the color unmellow yellow was formulated by Crayola in 1990. The color unmellow yellow is a fluorescent yellow to Laser Lemon. In crayons, the color may look a little bit orange-ish, the color is supposed to be fluorescent, but there is no mechanism to display fluorescence on a flat computer screen. Lemon is a color somewhat resembling yellow and named after the fruit, the color lemon is a representation of the color of the outer skin of a lemon
Shades of gray
Variations of gray or grey include achromatic grayscale shades, which lie exactly between white and black, and nearby colors with low colorfulness. A selection of a number of various colors is shown below. Below is a showing the computer web color grays. An achromatic gray is a color in which the red, green. The web colors gray, light gray, dark gray, a chromatic gray is a gray color in which the red and blue codes are not exactly equal, but are close to each other, which is what makes it a shade of gray. The colors white and black are not usually thought of as shades of gray, since achromatic colors have no hue, the hue code is left blank for achromatic colors. A white visual stimulation will be void of hue and grayness, white is the lightest possible color. Black is the color of objects that do not emit or reflect light in any part of the visible spectrum, black is the darkest possible color. Achromatic grays are colors in which the rgb values are exactly equal, since achromatic grays have no hue, the hue code is indicated with a dash.
Achromatic grays are the axis of the sphere, with white at the north pole. The various tones of gray are along the axis of the color sphere from white at the top of the axis to black at the bottom of the axis. At right is displayed the web color gainsboro, gainsboro is a pale tone of gray. There is no evidence the name gainsboro was used as a name before it was included as one of the X11 colors when they were formulated in 1987. At right is displayed the web color light gray, displayed at right is the web color silver. This color is a representation of the color of the metal silver This is supposed to be a color, however. At right is displayed the color gray, or gray in the X11 color names. The coordinates in the X11 were set at 190 to avoid gray being displayed as white on 2-bit grayscale displays, see the chart Color names that clash between X11 and HTML/CSS in the X11 color names article to see those colors which are different in HTML/CSS and X11. At right is displayed the dark medium gray, or dark gray in the X11 color names
A green apple for instance looks green to us at midday, when the main illumination is white sunlight, and at sunset, when the main illumination is red. Color vision is a process by which organisms and machines are able to distinguish based on the different wavelengths of light reflected, transmitted. Color constancy is a process allows the brain to recognize a familiar object as being a consistent color regardless of the amount or wavelengths of light reflecting from it at a given moment. These specialized cells are called double-opponent cells because they compute both color opponency and spatial opponency, double-opponent cells were first described by Nigel Daw in the goldfish retina. Color constancy works only if the incident illumination contains a range of wavelengths, the different cone cells of the eye register different but overlapping ranges of wavelengths of the light reflected by every object in the scene. From this information, the system attempts to determine the approximate composition of the illuminating light.
This illumination is discounted in order to obtain the true color or reflectance. This reflectance largely determines the perceived color, the effect was described in 1971 by Edwin H. Land, who formulated retinex theory to explain it. The word retinex is a formed from retina and cortex. The effect can be demonstrated as follows. A display called a Mondrian consisting of colored patches is shown to a person. The display is illuminated by three white lights, one projected through a red filter, one projected through a green filter, the person is asked to adjust the intensity of the lights so that a particular patch in the display appears white. The experimenter measures the intensities of red, the experimenter asks the person to identify the color of a neighboring patch, for example, appears green. Then the experimenter adjusts the lights so that the intensities of red, the person shows color constancy in that the green patch continues to appear green, the white patch continues to appear white, and all the remaining patches continue to have their original colors.
Color constancy is a feature of computer vision, and many algorithms have been developed for this purpose. These algorithms receive as input the red/green/blue values of each pixel of the image, one such algorithm operates as follows, the maximal red value rmax of all pixels is determined, and the maximal green value gmax and the maximal blue value bmax. For each pixel with values its reflectance is estimated as, the original retinex algorithm proposed by Land and McCann uses a localized version of this principle. Although retinex models are widely used in computer vision, actual human color perception has been shown to be more complex
Structural coloration is the production of colour by microscopically structured surfaces fine enough to interfere with visible light, sometimes in combination with pigments. For example, peacock feathers are pigmented brown, but their microscopic structure makes them reflect blue and green light. Structural coloration was first observed by English scientists Robert Hooke and Isaac Newton, Young described iridescence as the result of interference between reflections from two or more surfaces of thin films, combined with refraction as light enters and leaves such films. The geometry determines that at certain angles, the light reflected from both surfaces interferes constructively, while at other angles, the light interferes destructively, different colours therefore appear at different angles. Some cuts of meat show structural coloration due to the exposure of the arrangement of the muscular fibres. Many of these photonic mechanisms correspond to elaborate structures visible by electron microscopy, in plants, brilliant colours are produced by structures within cells.
In his 1704 book Opticks, Isaac Newton described the mechanism of the other than the brown pigment of peacock tail feathers. Thomas Young extended Newtons particle theory of light by showing that light could behave as a wave. He showed in 1803 that light could diffract from sharp edges or slits, Colours of the latter kind are often spoken of as structural colours, they are caused by the structure of the coloured surfaces. The metallic lustre of the feathers of birds, such as the humming birds, is due to the presence of excessively fine striae upon the surface of the feathers. Structural coloration is caused by interference effects rather than by pigments, Colours are produced when a material is scored with fine parallel lines, formed of one or more parallel thin layers, or otherwise composed of microstructures on the scale of the colours wavelength. Structural coloration is responsible for the blues and greens of the feathers of birds, as well as many butterfly wings. These are often iridescent, as in peacock feathers and nacreous shells such as of pearl oysters and this is because the reflected colour depends on the viewing angle, which in turn governs the apparent spacing of the structures responsible.
Structural colours can be combined with pigment colours, peacock feathers are pigmented brown with melanin, iridescence, as explained by Thomas Young in 1803, is created when extremely thin films reflect part of the light falling on them from their top surfaces. The rest of the light goes through the films, and a part of it is reflected from their bottom surfaces. The two sets of reflected waves travel back upwards in the same direction, when the waves are one or more whole wavelength apart – in other words at certain specific angles, they add, giving a strong reflection. At other angles and phase differences, they can subtract, giving weak reflections, the thin film therefore selectively reflects just one wavelength – a pure colour – at any given angle, but other wavelengths – different colours – at different angles. So, as a structure like a butterflys wing or birds feather moves
A rainbow is a meteorological phenomenon that is caused by reflection and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky. It takes the form of a multicoloured arc, Rainbows caused by sunlight always appear in the section of sky directly opposite the sun. However, the observer sees only an arc formed by illuminated droplets above the ground. In a primary rainbow, the arc shows red on the outer part and this rainbow is caused by light being refracted when entering a droplet of water, reflected inside on the back of the droplet and refracted again when leaving it. In a double rainbow, an arc is seen outside the primary arc. A rainbow is not located at a distance from the observer. Thus, a rainbow is not an object and cannot be physically approached, indeed, it is impossible for an observer to see a rainbow from water droplets at any angle other than the customary one of 42 degrees from the direction opposite the light source. Even if an observer sees another observer who seems under or at the end of a rainbow, Rainbows span a continuous spectrum of colours.
Rainbows can be caused by many forms of airborne water and these include not only rain, but mist and airborne dew. Rainbows can be observed there are water drops in the air. Because of this, rainbows are seen in the western sky during the morning. The most spectacular rainbow displays happen when half the sky is dark with raining clouds. The result is a rainbow that contrasts with the darkened background. During such good visibility conditions, the larger but fainter secondary rainbow is often visible and it appears about 10° outside of the primary rainbow, with inverse order of colours. The rainbow effect is commonly seen near waterfalls or fountains. In addition, the effect can be created by dispersing water droplets into the air during a sunny day. Rarely, a moonbow, lunar rainbow or nighttime rainbow, can be seen on strongly moonlit nights, as human visual perception for colour is poor in low light, moonbows are often perceived to be white. It is difficult to photograph the complete semicircle of a rainbow in one frame, for a 35 mm camera, a wide-angle lens with a focal length of 19 mm or less would be required
Shades of pink
This article is about notable tints and shades of the color pink. These various colors are shown below, at right is displayed the web color pink. At right is displayed the web color light pink, the name of the web color is written as lightpink in HTML for computer display. Although this color is called pink, as can be ascertained by inspecting its hex code, it is actually a slightly deeper, not a lighter. A more accurate name for it in terms of color nomenclature would therefore be medium light pink. At right is displayed the web color hot pink, the name of the web color is written as hotpink in HTML for computer display. At right is displayed the web color deep pink, the name of the web color is written as deeppink in HTML for computer display. Displayed at right is the color champagne pink, the source of this color is the Pantone Textile Paper eXtended color list, color #12-1107 TPX—Champagne Pink. At right is displayed the color pink lace, the color name pink lace for this pale tone of rose pink has been in use since 2001, when it was promulgated as one of the colors on the Xona.
com Color List. This color is suggestive of the color of womens lingerie. The color piggy pink is displayed at right, the color piggy pink is a representation of the color of a pink pig. The color piggy pink was formulated by Crayola in 1998, the color was originally called pig pink, but the name was changed to piggy pink. At right is displayed the pale pink, a light. At right is displayed the color pink, a light shade of pink. The first recorded use of pink as a color name in English was in 1928. This is a recent tradition and until the 1940s the convention was exactly the opposite, pink was used for boys while girls were dressed in blue. Spanish pink is the color that is called Rosa in the Guía de coloraciones by Rosa Gallego and Juan Carlos Sanz, at right is displayed the color cameo pink, a medium light tone of rose pink. The first recorded use of pink as a color name in English was in 1912
Camellia is a genus of flowering plants in the family Theaceae. They are found in eastern and southern Asia, from the Himalayas east to Japan, there are 100–300 described species, with some controversy over the exact number. There are around 3,000 hybrids, the genus was named by Linnaeus after the Jesuit botanist Georg Joseph Kamel, who worked in the Philippines and described a species of camellia. Of economic importance in the Indian subcontinent and Asia, leaves of C. sinensis are processed to create the popular beverage, the ornamental C. japonica, C. sasanqua and their hybrids are the source of hundreds of garden cultivars. C. oleifera produces tea seed oil, used in cooking, Camellias are evergreen shrubs or small trees up to 20 m tall. Their leaves are arranged, thick, serrated. Their flowers are large and conspicuous, one to 12 cm in diameter. The colors of the flowers vary from white through pink colors to red, truly yellow flowers are only in South China. Camellia flowers throughout the genus are characterized by a bouquet of conspicuous yellow stamens.
The so-called fruit of plants is a dry capsule, sometimes subdivided in up to five compartments. The various species of plants are generally well-adapted to acidic soils rich in humus. Most species of camellias require an amount of water, either from natural rainfall or from irrigation. However, some of the more unusual camellias – typically species from karst soils in Vietnam – can grow too much water. Camellia plants usually have a growth rate. Typically they will grow about 30 cm per year until mature – though this does vary depending on their variety, Camellia plants are used as food plants by the larvae of a number of Lepidoptera species, see List of Lepidoptera that feed on Camellia. Leaves of the Japanese camellia are susceptible to the fungal parasite Mycelia sterile, Camellia sinensis, the tea plant, is of major commercial importance because tea is made from its leaves. The species C. sinensis is the product of generations of selective breeding in order to bring out qualities considered desirable for tea.
However, many other camellias can be used to produce a similar beverage, for example, in some parts of Japan, tea made from C. sasanqua leaves is popular
Color printing or colour printing is the reproduction of an image or text in color. The additive combination of any two colors in roughly equal proportion gives rise to the perception of a secondary color. For example and green yields yellow and blue yields magenta, yellow and magenta are merely the basic secondary colors, unequal mixtures of the primaries give rise to perception of many other colors all of which may be considered tertiary. While there are techniques for reproducing images in color, specific graphic processes. In this type of industrial or commercial printing, the used to print full-color images. Four inks are used, three colors plus black. These ink colors are cyan, magenta and key, cyan can be thought of as minus-red, magenta as minus-green, and yellow as minus-blue. These inks are semi-transparent or translucent, where two such inks overlap on the paper due to sequential printing impressions, a primary color is perceived. For example, yellow overprinted by magenta yields red, the secondary or subtractive colors cyan and yellow may be considered primary by printers and watercolorists.
Two graphic techniques are required to prepare images for four-color printing, in the pre-press stage, original images are translated into forms that can be used on a printing press, through color separation, and screening or halftoning. These steps make possible the creation of printing plates that can transfer color impressions to paper on printing presses based on the principles of lithography. An emerging method of printing is six-color process printing which adds orange and green to the traditional CMYK inks for a larger and more vibrant gamut. However, such alternate color systems still rely on color separation, color printing can involve as few as one color ink, or multiple color inks which are not the primary colors. Using a limited number of inks, or specific color inks in addition to the primary colors, is referred to as spot color printing. Generally, spot-color inks are specific formulations that are designed to print alone, the range of available spot color inks, much like paint, is nearly unlimited, and much more varied than the colors that can be produced by four-color-process printing.
Spot-color inks range from pastels to intense fluorescents to reflective metallics. Color printing involves a series of steps, or transformations, to generate a quality color reproduction, the following sections focus on the steps used when reproducing a color image in CMYK printing, along with some historical perspective. Woodblock printing on textiles preceded printing on paper in both Asia and Europe, and the use of different blocks to produce patterns in color was common
A colour cast is a tint of a particular colour, usually unwanted, which affects the whole, or portion, of a photographic image evenly. Certain types of light can cause film and digital cameras to have a colour cast, illuminating a subject with light sources of different colour temperatures will usually cause colour cast problems in the shadows. In general, the eye does not notice the unnatural colour, because our eyes and brains adjust. In film, colour casts can be caused by problems in development, improper timing or imbalanced chemical mixtures can cause unwanted casts. Colour casts can occur in old photographs due to fading of dyes and these may be correctable on a scanned version of the photograph with image editing techniques. High end digital cameras try to detect and compensate colour cast. Otherwise, photo editing programs, such as Photoshop, often have built in colour correction facilities, for film, blue filters and amber filters are used to counter casts. Amber filters are used to reduce the blueish tint caused by daylight, blue filters reduce the orange colour caused by incandescent light. A variety of coloured filters in varying degrees of intensity are available, kodaks amber filters, for example, vary from palest yellow to deepest amber. A photographer chooses which filter to use based on the quality of the ambient light, colour temperature meters can read the temperature of the existing lighting conditions and guide the selection of the filter.
Clouded sky, for example, requires a paler amber than clear blue sky, if a filter is unavailable, flash is an alternative solution which usually provides enough neutral white light to counter the cast. In the case of film, if photographs all contain the same cast, if the film itself does not contain any cast, it can be reused to create another set of photographs in proper chemical conditions. If the film contains a cast, filters can be used during processing to correct it