Color blindness or color vision deficiency (CVD) is the decreased ability to see color or differences in color. The severity of color blindness ranges from mostly unnoticeable to full absence of color perception. Color blindness is usually an inherited problem or variation in the functionality of one or more of the three classes of cone cells in the retina, which mediate color vision. The most common form is caused by a genetic condition called congenital red–green color blindness, which affects up to 1 in 12 males (8%) and 1 in 200 females (0.5%). The condition is more prevalent in males, because the opsin genes responsible are located on the X chromosome. Rarer genetic conditions causing color blindness include congenital blue–yellow color blindness, blue cone monochromacy, and achromatopsia. Color blindness can also result from physical or chemical damage to the eye, the optic nerve, parts of the brain, or from medication toxicity. Color vision also naturally degrades in old age.
Yellow is the color between green and orange on the spectrum of light. It is evoked by light with a dominant wavelength of roughly 575–585 nm. It is a primary color in subtractive color systems, used in painting or color printing. In the RGB color model, used to create colors on television and computer screens, yellow is a secondary color made by combining red and green at equal intensity. Carotenoids give the characteristic yellow color to autumn leaves, corn, canaries, daffodils, and lemons, as well as egg yolks, buttercups, and bananas. They absorb light energy and protect plants from photo damage in some cases. Sunlight has a slight yellowish hue when the Sun is near the horizon, due to atmospheric scattering of shorter wavelengths.
Purple is a color similar in appearance to violet light. In the RYB color model historically used in the arts, purple is a secondary color created by combining red and blue pigments. In the CMYK color model used in modern printing, purple is made by combining magenta pigment with either cyan pigment, black pigment, or both. In the RGB color model used in computer and television screens, purple is created by mixing red and blue light in order to create colors that appear similar to violet light.
A set of primary colors or primary colours consists of 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 that reflects the physics of how light interacts with physical media, and ultimately the retina.
Magenta is a purplish-red color. On color wheels of the RGB (additive) and CMY (subtractive) color models, it is located precisely midway between violet and red. It is one of the four colors of ink used in color printing by an inkjet printer, along with yellow, cyan, and black to make all the other colors. The tone of magenta used in printing, printer's magenta, is redder than the magenta of the RGB (additive) model, the former being closer to rose.
A pigment is a powder used to add color or change visual appearance. Pigments are completely or nearly insoluble and chemically unreactive in water or another medium; in contrast, dyes are colored substances which are soluble or go into solution at some stage in their use. Dyes are often organic compounds whereas pigments are often inorganic. Pigments of prehistoric and historic value include ochre, charcoal, and lapis lazuli.
Jasper Fforde is an English novelist, whose first novel, The Eyre Affair, was published in 2001. He is known mainly for his Thursday Next novels, but has published two books in the loosely connected Nursery Crime series and the first books of two other independent series: The Last Dragonslayer and Shades of Grey. Fforde's books abound in literary allusions and wordplay, tightly scripted plots and playfulness with the conventional, traditional genres. They usually contain elements of metafiction, parody, and fantasy.
Political colours are colours used to represent a political ideology, movement or party, either officially or unofficially. They represent the intersection of colour symbolism and political symbolism. Politicians making public appearances will often identify themselves by wearing rosettes, flowers, ties or ribbons in the colour of their political party. Parties in different countries with similar ideologies sometimes use similar colours. As an example the colour red symbolises left-wing ideologies in many countries, while the colour blue is often used for conservatism, the colour yellow is most commonly associated with liberalism and right-libertarianism, and Green politics is named after the ideology's political colour. The political associations of a given colour vary from country to country, and there are exceptions to the general trends, for example red has historically been associated with Christianity, but over time gained association with leftist politics, while the United States differs from other countries in that conservatism is associated with red and liberalism with blue. Mass media has driven a standardization of colour by political party, to simplify messaging, while historically the colour a candidate chose to identify with could have been chosen based on other factors such as family or regional variations.
Color theory, or more specifically traditional color theory, is the historical body of knowledge describing the behavior of colors, namely in color mixing, color contrast effects, color harmony, color schemes and color symbolism. Modern color theory is generally referred to as Color science. While there is no clear distinction in scope, traditional color theory tends to be more subjective and have artistic applications, while color science tends to be more objective and have functional applications, such as in chemistry, astronomy or color reproduction. Color theory dates back at least as far as Aristotle's treatise On Colors. A formalization of "color theory" began in the 18th century, initially within a partisan controversy over Isaac Newton's theory of color and the nature of primary colors. By the end of the 19th century, a schism had formed between traditional color theory and color science.
A color term is a word or phrase that refers to a specific color. The color term may refer to human perception of that color which is usually defined according to the Munsell color system, or to an underlying physical property. There are also numerical systems of color specification, referred to as color spaces.
A man-eating plant is a legendary carnivorous plant large enough to kill and consume a human or other large animal. Various such myths and fictional tales exist around the world.
Lavender is a light shade of purple or violet. It applies particularly to the color of the flower of the same name. The web color called lavender is displayed adjacent—it matches the color of the palest part of the flower; however, the more saturated color shown as floral lavender more closely matches the average color of the lavender flower as shown in the picture and is the tone of lavender historically and traditionally considered lavender by average people as opposed to website designers. The color lavender might be described as a medium purple or a light pinkish-purple. The term lavender may be used in general to apply to a wide range of pale, light, or grayish-purples, but only on the blue side; lilac is pale purple on the pink side. In paints, the color lavender is made by mixing purple and white paint.
Laurentien was a Canadian brand of art supplies owned by Sanford Canada. The line of supplies included coloured pencils, markers and crayons. The line of Laurentian coloured pencils was discontinued around 2012 and their websites no longer exist. Laurentien was marketed in the United States under the name Paradise.
Varieties of the color red may differ in hue, chroma or lightness, or in two or three of these qualities. Variations in value are also called tints and shades, a tint being a red or other hue mixed with white, a shade being mixed with black. A large selection of these various colors are shown below.
Lincoln green is the colour of dyed woollen cloth formerly originating in Lincoln, England, a major cloth town during the high Middle Ages. The dyers of Lincoln, known for colouring wool with woad to give it a strong blue shade, created the eponymous Lincoln green by overdyeing this blue wool with yellow weld or dyers' broom, Genista tinctoria. Other colours like "Coventry blue" and "Kendal green" were linked to the dyers of different English towns.
There are numerous variations of the color purple, a sampling of which is shown below.
Chinese pigments are the traditional medium to execute traditional Chinese brush paintings, besides ink. Chinese pigments is similar to Western gouache paint in that it contains more glue than watercolours, but more so than gouache. The high glue content makes the pigment bind better to Chinese paper and silk as well as enabling works of art to survive the wet-mounting process of Chinese hanging scroll mountings without smudging or bleeding.
Red pigments are materials, usually made from minerals, used to create the red colors in painting and other arts. The color of red and other pigments is determined by the way it absorbs certain parts of the spectrum of visible light and reflects the others. The brilliant opaque red of vermillion, for example, results because vermillion reflects the major part of red light, but absorbs the blue, green and yellow parts of white light.
