Color or colour is the visual perception based on the electromagnetic spectrum. Though color is not an inherent property of matter, color perception is related to an object's light absorption, reflection, emission spectra, and interference. For most humans, colors are perceived in the visible light spectrum with three types of cone cells (trichromacy). Other animals may have a different number of cone cell types or have eyes sensitive to different wavelengths, such as bees that can distinguish ultraviolet, and thus have a different color sensitivity range. Animal perception of color originates from different light wavelength or spectral sensitivity in cone cell types, which is then processed by the brain.
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.
Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495–570 nm. In subtractive color systems, used in painting and color printing, it is created by a combination of yellow and cyan; in the RGB color model, used on television and computer screens, it is one of the additive primary colors, along with red and blue, which are mixed in different combinations to create all other colors. By far the largest contributor to green in nature is chlorophyll, the chemical by which plants photosynthesize and convert sunlight into chemical energy. Many creatures have adapted to their green environments by taking on a green hue themselves as camouflage. Several minerals have a green color, including the emerald, which is colored green by its chromium content.
Indigo is a term used for a number of hues in the region of blue. The word comes from the ancient dye of the same name. The term "indigo" can refer to the color of the dye, various colors of fabric dyed with indigo dye, a spectral color, one of the seven colors of the rainbow as described by Newton, or a region on the color wheel, and can include various shades of blue, ultramarine, and green-blue. Since the web era, the term has also been used for various purple and violet hues identified as "indigo", based on use of the term "indigo" in HTML web page specifications.
A pastel is an art medium that consist of powdered pigment and a binder. It can exist in a variety of forms, including a stick, a square, a pebble, or a pan of color, though other forms are possible. The pigments used in pastels are similar to those used to produce some other colored visual arts media, such as oil paints; the binder is of a neutral hue and low saturation. The color effect of pastels is closer to the natural dry pigments than that of any other process.
Red is the color at the long wavelength end of the visible spectrum of light, next to orange and opposite violet. It has a dominant wavelength of approximately 625–740 nanometres. It is a primary color in the RGB color model and a secondary color in the CMYK color model, and is the complementary color of cyan. Reds range from the brilliant yellow-tinged scarlet and vermillion to bluish-red crimson, and vary in shade from the pale red pink to the dark red burgundy.
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.
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. The most common color mixing models are the additive primary colors and the subtractive primary colors.
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.
Pink is the color of a namesake flower that is a pale tint of red. It was first used as a color name in the late 17th century. According to surveys in Europe and the United States, pink is the color most often associated with charm, politeness, sensitivity, tenderness, sweetness, childhood, femininity, and romance. A combination of pink and white is associated with innocence, whereas a combination of pink and black links to eroticism and seduction. In the 21st century, pink is seen as a symbol of femininity, though it has not always been seen this way. In the 1920s, pink was seen as a color that reflected masculinity.
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.
Cadmium pigments are a class of pigments that contain cadmium. Most of the cadmium produced worldwide has been for use in rechargeable nickel–cadmium batteries, which have been replaced by other rechargeable nickel-chemistry cell varieties such as NiMH cells, but about half of the remaining consumption of cadmium, which is approximately 2,000 tonnes annually, is used to produce colored cadmium pigments. The principal pigments are a family of yellow, orange and red cadmium sulfides and sulfoselenides, as well as compounds with other metals.
Azure is the color between cyan and blue on the spectrum of visible light. It is often described as the color of the sky on a clear day.
Viridian is a blue-green pigment, a hydrated chromium(III) oxide, of medium saturation and relatively dark in value. It is composed of a majority of green, followed by blue. The first recorded use of viridian as a color name in English was in the 1860s. Viridian takes its name from the Latin viridis, meaning "green". The pigment was first prepared in mid-19th-century Paris and remains available from several US manufacturers as prepared artists' colors in all media.
In color theory, a tint is a mixture of a color with white, which increases lightness, while a shade is a mixture with black, which increases darkness. Both processes affect the resulting color mixture's relative saturation. A tone is produced either by mixing a color with gray, or by both tinting and shading. Mixing a color with any neutral color reduces the chroma, or colorfulness, while the hue remains unchanged.
Varieties of the color green 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 green or other hue mixed with white, a shade being mixed with black. A large selection of these various colors is shown below.
Historic paint analysis, or architectural paint research, is the scientific analysis of a broad range of architectural finishes, and is primarily used to determine the color and behavior of surface finishes at any given point in time. This helps us to understand the building's structural history and how its appearance has changed over time.
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.
Varieties of the color blue 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 blue or other hue mixed with white, a shade being mixed with black. A large selection of these colors is shown below.
Shades of black, or off-black colors, 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. Colors often considered "shades of black" include onyx, black olive, charcoal, and jet.
