The Austro-Hungarian Army was the ground force of the Austro-Hungarian Dual Monarchy from 1867 to 1918. It was composed of three parts: the joint army, the Imperial Austrian Landwehr, the Royal Hungarian Honvéd. In the wake of fighting between the Austrian Empire and the Hungarian Kingdom and the two decades of uneasy co-existence following, Hungarian soldiers served either in mixed units or were stationed away from Hungarian areas. With the Austro-Hungarian Compromise of 1867 the new tripartite army was brought into being, it existed until the disestablishment of the Austro-Hungarian Empire following World War I in 1918. The joint "Imperial and Royal Army" units were poorly trained and had limited access to new equipment because the governments of the Austrian and Hungarian parts of the empire preferred to generously fund their own units instead of outfitting all three army branches equally. All of the Honvédség and the Landwehr regiments were composed of three battalions, while the joint army k.u.k.
Regiments had four. The long-standing white infantry uniforms were replaced in the half of the 19th century with dark blue tunics, which in turn were replaced by a pike grey uniform used in the initial stages of World War I. In September 1915, field gray was adopted as the new official uniform colour; the last known surviving member of the Austro-Hungarian Army was World War I veteran Franz Künstler, who died in May 2008 at the age of 107. The major decisions 1867-1895 were made by Archduke Albrecht, Duke of Teschen, the nephew of the Emperor Franz Joseph and his leading advisor in military affairs. According to historians John Keegan and Andrew Wheatcroft: He was a firm conservative in all matters and civil, took to writing pamphlets lamenting the state of the Army’s morale as well as fighting a fierce rearguard action against all forms of innovation…. Much of the Austrian failure in the First World War can be traced back to his long period of power…, his power was that of the bureaucrat, not the fighting soldier, his thirty years of command over the peacetime Habsburg Army made it a flabby instrument of war.
Austria-Hungary avoided major wars in the era between 1867 and 1914 but engaged in a number of minor military actions. The general staff maintained plans for major wars against neighboring powers Italy and Russia. By contrast, the main enemies Russia and Serbia had engaged in large scale warfare in the decade before the First World War. In the late 19th century the army was used to suppress unrest in urban areas of the empire: in 1882 and 1887 in Vienna and notably against German nationalists at Graz and Czech nationalists in Prague in November 1897. Soldiers under the command of Conrad von Hotzendorf were used against Italian rioters in Trieste in 1902; the most significant action by soldiers of the Dual Monarchy in this period was the Austro-Hungarian occupation of Bosnia and Herzegovina in the summer of 1878. When troops under the command of Josip Filipović and Stjepan Jovanović entered the provinces expecting little or no resistance, they were met with ferocious opposition from elements of both Muslim and Orthodox populations there.
Despite setbacks at Maglaj and Tuzla, Sarajevo was occupied in October. Austro-Hungarian casualties amounted to over 5,000 and the unexpected violence of the campaign led to recriminations between commanders and political leaders. In 1868, the number of active-duty troops in the army was 355,000, the total could be expanded to 800,000 upon mobilization. However, this was less than the European powers of France, the North German Confederation and Russia, each of which could field more than one million men. Though the population of the empire had risen to nearly 50 million by 1900, the size of the army was tied to ceilings established in 1889. Thus, at the start of the 20th century, Austria-Hungary conscripted only 0.29% of its population, compared to 0.47% in Germany, 0.35% in Russia and 0.75% in France. The 1889 army law was not revised until 1912; the ethnic make-up of the enlisted ranks reflected the diversity of the empire. From a religious standpoint, the Austro-Hungarian army officer corps was dominated by Roman Catholics.
In 1896, out of 1000 officers, 791 were Roman Catholics, 86 Protestants, 84 Jews, 39 Greek-Orthodox, one Uniate. Of the pre–World War military forces of the major European powers, the Austro-Hungarian army was alone in its regular promotion of Jews to positions of command. While the Jewish population of the lands of the Dual Monarchy 4.4% including Bosnia-Herzegovna), Jews made up nearly 18% of the reserve officer corps. There were no official barriers to military service for Jews, but in years this tolerance eroded to some extent, as important figures such as Conrad von Hötzendorf and Archduke Franz Ferdinand sometimes expressed anti-Jewish sentiments. Franz Ferdinand was accused of discriminating against Protestant officers. Following the 1867 constitutional arrangements, the Reichsrat was dominated by German Liberals, who regarded the army as a relic of feudalism. In Budapest, legislators were reluctant to authorize funds for the joint army but were generous with the Hungarian branch of the army, the Honvédség.
In 1867 the military budget accounte
The Green Howards known as the Yorkshire Regiment until the 1920s, was a line infantry regiment of the British Army, in the King's Division. Raised in 1688, it served under various titles until it was amalgamated with the Prince of Wales's Own Regiment of Yorkshire and the Duke of Wellington's Regiment, all Yorkshire-based regiments in the King's Division, to form the Yorkshire Regiment on 6 June 2006; the regiment was raised by Colonel Francis Luttrell in 1688 from independent companies of infantry in Devon. It embarked for Flanders in spring 1692 and saw action at the Battle of Steenkerque in August 1692, the Battle of Landen in July 1693 and the Siege of Namur in summer 1695 during the Nine Years' War; the regiment returned to England in March 1696. The regiment returned to Flanders in spring 1710 and took part in the siege of Douai in summer 1710 during the War of the Spanish Succession; the regiment returned to Flanders again in 1744 and saw action at the Battle of Fontenoy in May 1745, the Battle of Rocoux in October 1746 and the Battle of Lauffeld in July 1747 during the War of the Austrian Succession.
The regiment returned to England in winter 1748. The regiment was known by the names of its various colonels until 1751, when it became the 19th Regiment of Foot; the regiment took part in the capture of Belle Île in April 1761 during the Seven Years' War. In 1782, all regiments of foot without a special designation were given a county title "to cultivate a connection with the County which might at all times be useful towards recruiting" and so the regiment was redesignated the 19th Regiment; the regiment saw action at the Siege of Seringapatam in April 1799 during the Fourth Anglo-Mysore War. The regiment was known as the Green Howards from 1744. At that time, regiments were known by the name of their colonel; the 19th regiment's colonel was Hon. Sir Charles Howard. However, at the same time, the 3rd Regiment of Foot had been commanded by its colonel Thomas Howard, since 1737. To tell them apart, the colours of their uniform facings were used to distinguish them. In this way, one became'Howard's Buffs'.
Although the Green Howards were referred to unofficially as such from on, it was not until 1921 that the regiment was retitled as the Green Howards. Under the Childers Reforms, all non-royal English infantry regiments were to wear white facings from 1881. In 1899, the regiment was able to reverse this decision with the restoration of the grass green facings worn by the 19th Foot. In April 1801 the regiment was deployed to Ceylon for service in the Kandyan Wars; the regiment lost 6 officers and 172 other ranks in a massacre there in June 1803 and remained on the island to enforce British rule. The regiment did not return to England until May 1820; the regiment saw action at the Battle of Alma in September 1854 and at the Siege of Sevastopol in winter 1854 during the Crimean War and saw action again during the Indian Rebellion. In 1875, Princess Alexandra, Princess of Wales presented new colours to the 1st Battalion at Sheffield, consented to the regiment bearing her name, thus becoming the 19th Regiment of Foot.
The regiment adopted a cap badge consisting of the Princess's cypher "A" combined with the Dannebrog or Danish cross and topped by her coronet. The Princess became Queen Alexandra in 1901, was the regiment's Colonel-in-Chief from 1914 until her death in 1925; the regiment was not fundamentally affected by the Cardwell Reforms of the 1870s, which gave it a depot at Richmond Barracks in North Yorkshire from 1873, or by the Childers reforms of 1881 – as it possessed two battalions, there was no need for it to amalgamate with another regiment. Under the reforms the regiment amalgamated with the militia battalions and rifle volunteers in its designated regimental district and became The Princess of Wales's Own on 1 July 1881; the 1st battalion was stationed at Nova Scotia from 1884, moved to the Mediterranean in 1888 where it was stationed at Malta but saw action in Egypt moved to Jersey in 1895 followed by Ireland in 1898. After a brief spell in Gibraltar in 1899, the battalion was posted to South Africa as reinforcement for the Second Boer War, where it was involved in the Relief of Kimberley and the battles of Diamond Hill and Belfast.
The battalion returned to the United Kingdom in September 1902. The 2nd battalion was in Ireland from 1881 to 1886, when it returned to garrison back home in England. From early 1890 the battalion was stationed in British India, where it took part in military campaigns on the North-West Frontier; the battalion had various postings, including at Sitapur and Benares until late 1902 when it was posted to Cawnpore. A 3rd Battalion, formed from the 5th West York Militia in 1881 was a reserve battalion, it was embodied in December 1899, 700 men embarked on the SS Assaye in February 1900 for service in South Africa during the Second Boer War. Many of the officers and men returned home in May 1902 on the SS Sicilia; the 4th Battalion, formed from the North York Rifles in 1881 was a reserve battalion. It was embodied for service on 5 May 1900, disembodied on 2 July 1901, re-embodied again for service during Second Boer War in South Africa. 555 officers and men returned to Southampton by the SS Tagus in October 1902, following the end of the war, was disbanded at the Richmond barracks.
In July 1902, the regiment was
Lincoln green is the colour of dyed woollen cloth 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 overdying 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. Lincoln green is associated with Robin Hood and his Merry Men in Sherwood Forest, Nottinghamshire; the first recorded use of Lincoln green as a colour name in English was in 1510. By the late sixteenth century, Lincoln green was a thing of the past. Michael Drayton provided a sidenote in his Poly-Olbion: "Lincoln anciently dyed the best green in England." Cloth of Lincoln green was more pleasing than undyed shepherd's gray cloth: "When they were clothed in Lyncolne grene they kest away their gray", according to A Lytell Geste of Robyn Hode, ca 1510, Lincoln green betokened an old-fashioned forester in the fancy dress of Edmund Spenser's The Faery Queene: "All in a woodman's jacket he was clad of Lincolne Greene, belay'd with silver lace."
Robin Hood's Garland, the popular ballad printed in eighteenth-century compilations, offers an unexpected picture of Robin as he presented himself at court: He cloathed his men in Lincoln greenAnd himself in scarlet red" The distinction was in the cost of scarlet, dyed with kermes, derived from the Kermes vermilio insect native to the Mediterranean. Lincoln scarlet, from its imported dyestuff, was more expensive than Lincoln green. In 1198 the Sheriff of Lincoln bought ninety ells of scarlet cloth for £30. In 1182 the Sheriff of Lincoln bought Scarlet at 6s 8d/ell and Blanchet both at 3s/ell and Gray at 1s 8d/ell. By 1216 three guilds controlling the cloth trade were established in Lincoln, the Weavers', Dyers', Fullers' guilds. "Lincoln-green" was revived in the years prior to the Great War, when it was adopted as the colour of the full-dress uniform of the Lincolnshire Yeomanry. This military version took the form of a distinctively light shade, which contrasted with the sombre rifle green worn by other regiments of the British Army.
Geoffrey Chaucer 1387–1400 The Canterbury Tales The Friar's Tale has the Corrupt Summoner meeting a devil disguised as a Yeoman dressed in Lincoln Green Sir Walter Scott in his 1820 novel Ivanhoe mentioned Lincoln green three times: in Chapter 7, Chapter 15, Chapter 23. William Makepeace Thackeray in his 1848 novel Vanity Fair mentioned Lincoln green in Chapter III: "What causes them to labour at piano-forte sonatas, to learn four songs from a fashionable master at a guinea a lesson, to play the harp if they have handsome arms and neat elbows, to wear Lincoln Green toxopholite hats and feathers, but that they may bring down some "desirable" young man with those killing bows and arrows of theirs?" The colour appears used in the dystopian novel Shades of Grey 1: The Road to High Saffron by Jasper Fforde, in which shades of green—and Lincoln green in particular—have narcotic effects. List of colours
International Standard Book Number
The International Standard Book Number is a numeric commercial book identifier, intended to be unique. Publishers purchase ISBNs from an affiliate of the International ISBN Agency. An ISBN is assigned to each variation of a book. For example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN; the ISBN is 13 digits long if assigned on or after 1 January 2007, 10 digits long if assigned before 2007. The method of assigning an ISBN is nation-based and varies from country to country depending on how large the publishing industry is within a country; the initial ISBN identification format was devised in 1967, based upon the 9-digit Standard Book Numbering created in 1966. The 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO 2108. Published books sometimes appear without an ISBN; the International ISBN agency sometimes assigns such books ISBNs on its own initiative.
Another identifier, the International Standard Serial Number, identifies periodical publications such as magazines and newspapers. The International Standard Music Number covers musical scores; the Standard Book Numbering code is a 9-digit commercial book identifier system created by Gordon Foster, Emeritus Professor of Statistics at Trinity College, for the booksellers and stationers WHSmith and others in 1965. The ISBN identification format was conceived in 1967 in the United Kingdom by David Whitaker and in 1968 in the United States by Emery Koltay; the 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO 2108. The United Kingdom continued to use the 9-digit SBN code until 1974. ISO has appointed the International ISBN Agency as the registration authority for ISBN worldwide and the ISBN Standard is developed under the control of ISO Technical Committee 46/Subcommittee 9 TC 46/SC 9; the ISO on-line facility only refers back to 1978.
An SBN may be converted to an ISBN by prefixing the digit "0". For example, the second edition of Mr. J. G. Reeder Returns, published by Hodder in 1965, has "SBN 340 01381 8" – 340 indicating the publisher, 01381 their serial number, 8 being the check digit; this can be converted to ISBN 0-340-01381-8. Since 1 January 2007, ISBNs have contained 13 digits, a format, compatible with "Bookland" European Article Number EAN-13s. An ISBN is assigned to each variation of a book. For example, an ebook, a paperback, a hardcover edition of the same book would each have a different ISBN; the ISBN is 13 digits long if assigned on or after 1 January 2007, 10 digits long if assigned before 2007. An International Standard Book Number consists of 4 parts or 5 parts: for a 13-digit ISBN, a prefix element – a GS1 prefix: so far 978 or 979 have been made available by GS1, the registration group element, the registrant element, the publication element, a checksum character or check digit. A 13-digit ISBN can be separated into its parts, when this is done it is customary to separate the parts with hyphens or spaces.
Separating the parts of a 10-digit ISBN is done with either hyphens or spaces. Figuring out how to separate a given ISBN is complicated, because most of the parts do not use a fixed number of digits. ISBN is most used among others special identifiers to describe references in Wikipedia and can help to find the same sources with different description in various language versions. ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency, responsible for that country or territory regardless of the publication language; the ranges of ISBNs assigned to any particular country are based on the publishing profile of the country concerned, so the ranges will vary depending on the number of books and the number and size of publishers that are active. Some ISBN registration agencies are based in national libraries or within ministries of culture and thus may receive direct funding from government to support their services. In other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded.
A full directory of ISBN agencies is available on the International ISBN Agency website. Partial listing: Australia: the commercial library services agency Thorpe-Bowker.
A division is a large military unit or formation consisting of between 10,000 and 20,000 soldiers. Infantry divisions during the World Wars ranged between 30,000 in nominal strength. In most armies, a division is composed of several brigades; the division has been the default combined arms unit capable of independent operations. Smaller combined arms units, such as the American regimental combat team during World War II, were used when conditions favored them. In recent times, modern Western militaries have begun adopting the smaller brigade combat team as the default combined arms unit, with the division they belong to being less important. While the focus of this article is on army divisions, in naval usage division has a different meaning, referring to either an administrative/functional sub-unit of a department aboard naval and coast guard ships, shore commands, in naval aviation units, to a sub-unit of several ships within a flotilla or squadron, or to two or three sections of aircraft operating under a designated division leader.
Some languages, like Russian, Serbo-Croatian and Polish, use a similar word divizion/dywizjon for a battalion-size artillery or cavalry unit. In administrative/functional sub-unit usage, unit size varies though divisions number far fewer than 100 people and are equivalent in function and organizational hierarchy/command relationship to a platoon or flight. In the West, the first general to think of organising an army into smaller combined-arms units was Maurice de Saxe, Marshal General of France, in his book Mes Rêveries, he died without having implemented his idea. Victor-François de Broglie put the ideas into practice, he conducted successful practical experiments of the divisional system in the Seven Years' War. The first war in which the divisional system was used systematically was the French Revolutionary War. Lazare Carnot of the Committee of Public Safety, in charge of military affairs, came to the same conclusion about it as the previous royal government, the army was organised into divisions.
It made the armies more flexible and easy to maneuver, it made the large army of the revolution manageable. Under Napoleon, the divisions were grouped together because of their increasing size. Napoleon's military success spread the corps system all over Europe; the divisional system reached its numerical height during the Second World War. The Soviet Union's Red Army consisted of more than a thousand divisional-size units at any one time, the total number of rifle divisions raised during the Great Patriotic War is estimated at 2,000. Nazi Germany had hundreds of numbered and/or named divisions, while the United States employed 91 divisions, two of which were disbanded during the war. A notable change to divisional structures during the war was completion of the shift from square divisions to triangular divisions that many European nations started using in World War I; this was done to pare down chain of command overhead. The triangular division allowed the tactic of "two forward, one back", where two of the division's regiments would be engaging the enemy with one regiment in reserve.
All divisions in World War II were expected to have their own artillery formations the size of a regiment depending upon the nation. Divisional artillery was seconded by corps level command to increase firepower in larger engagements. Regimental combat teams were used by the US during the war as well, whereby attached and/or organic divisional units were parceled out to infantry regiments, creating smaller combined-arms units with their own armor and artillery and support units; these combat teams would still be under divisional command but have some level of autonomy on the battlefield. Organic units within divisions were units which operated directly under Divisional command and were not controlled by the Regiments; these units were support units in nature, include signal companies, medical battalions, supply trains and administration. Attached units were smaller units that were placed under Divisional command temporarily for the purpose of completing a particular mission; these units were combat units such as tank battalions, tank destroyer battalions and cavalry reconnaissance squadrons.
In modern times, most military forces have standardized their divisional structures. This does not mean that divisions are equal in size or structure from country to country, but divisions have, in most cases, come to be units of 10,000 to 20,000 troops with enough organic support to be capable of independent operations; the direct organization of the division consists of one to four brigades or battle groups of its primary combat arm, along with a brigade or regiment of combat support and a number of direct-reporting battalions for necessary specialized support tasks, such as intelligence, logistics and combat engineers. Most militaries standardize ideal organization strength for each type of division, encapsulated in a Table of Organization and Equipment which specifies exact assignments of units and equipment for a division; the modern division became the primary identifiable combat unit in many militaries during the second half of the 20th century, supplanting the brigade.
The Suffolk Regiment was an infantry regiment of the line in the British Army with a history dating back to 1685. It saw service for three centuries, participating in many wars and conflicts, including the First and Second World Wars, before being amalgamated with the Royal Norfolk Regiment to form the 1st East Anglian Regiment in 1959 which, in 1964, was further amalgamated with the 2nd East Anglian Regiment, the 3rd East Anglian Regiment and the Royal Leicestershire Regiment to create the present Royal Anglian Regiment; the regiment was raised by Henry Howard, 7th Duke of Norfolk as the Duke of Norfolk's Regiment of Foot in 1685 and incorporated men from the East Anglian counties of Norfolk and Suffolk. It was formed to combat the Monmouth Rebellion, but was not disbanded when the rebellion was defeated. Following the 1688 Glorious Revolution its Colonel Lord Lichfield was dismissed for his sympathies with James II and was replaced by Henry Wharton. Under Wharton the regiment participated in Marshal Schomberg's expedition to Ireland in 1689.
It captured the unoccupied town of Belfast and took part in the Siege of Carrickfergus in August 1689. Wharton died of fever in October 1689. Richard Brewer took command of the regiment and led it at the Battle of the Boyne in July 1690, the Capture of Waterford in July 1690 and the Siege of Limerick in August 1690; the regiment fought at the Siege of Athlone in June 1691 and the Surrender of Limerick in August 1691 before returning to England in the year. The regiment saw action at the attack Fort Knokke during the Nine Years' War in Flanders; the regiment was placed on the Irish establishment following the Treaty of Ryswick in 1697, was not disbanded. It was subsequently stationed in Jamaica during the War of the Spanish Succession, it embarked for Flanders in 1742 for service in the War of the Austrian Succession and fought at the Battle of Dettingen in June 1743 and the Battle of Fontenoy in May 1745. The regiment was ranked in 1747 as the 12th Foot regiment and renamed as the 12th Regiment of Foot in 1751.
In 1758 the 2nd Battalion of the regiment was separated from it and formed the basis of the 65th Regiment of Foot. The regiment embarked for Germany in summer 1758 for service in the Seven Years' War. In 1782, it was given a county association as the 12th Regiment of Foot; the regiment embarked for the West Indies in 1793 and took part in the capture of Martinique, Saint Lucia and Guadeloupe in 1794. It returned to England in 1795 and embarked for India in 1796 where it took part in operations against Tipu Sultan including the Siege of Seringapatam in April 1799 during the Fourth Anglo-Mysore War, it took part in the Invasion of Île Bonaparte in July 1810 and the Invasion of Isle de France in November 1810 during the Napoleonic Wars. While garrisoning the Australian Colony of Victoria in 1854, detachments from the regiment, the 40th Regiment of Foot and colonial police, suppressed the Eureka Rebellion, by gold prospectors at Ballarat; the regiment was not fundamentally affected by the Cardwell Reforms of the 1870s, which gave it a depot at Gibraltar Barracks in Bury St Edmunds from 1873, or by the Childers reforms of 1881 – as it possessed two battalions, there was no need for it to amalgamate with another regiment.
Under the reforms the regiment became the Suffolk Regiment on 1 July 1881. As the county regiment of Suffolk, it gained the county's militia and rifle volunteer battalions, which were integrated into the regiment as numbered battalions; the 1st Battalion served in the Second Boer War: it assaulted a hill near Colesberg in January 1900 and suffered many casualties including the commanding officer. By contrast between 1895 and 1914, the 2nd Battalion, Suffolk Regiment was not involved in hostilities, it was stationed for the majority of the time in India. Garrison postings during this period include. During its service in India the 2nd Battalion became known as a "well officered battalion that compared favourably with the best battalion in the service having the nicest possible feeling amongst all ranks"; the 2nd was regarded as a good shooting battalion with high level of musketry skills. The spirit of independence and self-reliance exhibited by officers and non-commissioned officers led to the 2nd Battalion taking first place in the Quetta Division of the British Army of India, from a military effectiveness point of view, in a six-day test.
This test saw the men under arms for over 12 hours a day conducting a wide selection of military manoeuvres, including bridge building, retreats under fire, forced marches and defending ground and fixed fortifications. In 1908, the Volunteers and Militia were reorganised nationally, with the former becoming the Territorial Force and the latter the Special Reserve; the 1st Battalion landed at Le Havre as part of the 84th Brigade in the 28th Division in January 1915 for service on the Western Front and transferred to Egypt in 24 October 1915. It suffered some 400 casualties at the Second Battle of Ypres in May 1915; the 2nd Battalion landed at landed at Le Havre as part of the 14th Brigade in the 5th Division in August 1914. The valu
Color, or colour, is the characteristic of human visual perception described through color categories, with names such as red, yellow, blue, or purple. This perception of color derives from the stimulation of cone cells in the human eye by electromagnetic radiation in the visible spectrum. Color categories and physical specifications of color are associated with objects through the wavelength of the light, reflected from them; this reflection is governed by the object's physical properties such as light absorption, emission spectra, etc. By defining a color space, colors can be identified numerically by coordinates, which in 1931 were named in global agreement with internationally agreed color names like mentioned above by the International Commission on Illumination; the RGB color space for instance is a color space corresponding to human trichromacy and to the three cone cell types that respond to three bands of light: long wavelengths, peaking near 564–580 nm. There may be more than three color dimensions in other color spaces, such as in the CMYK color model, wherein one of the dimensions relates to a color's colorfulness).
The photo-receptivity of the "eyes" of other species varies from that of humans and so results in correspondingly different color perceptions that cannot be compared to one another. Honeybees and bumblebees for instance have trichromatic color vision sensitive to ultraviolet but is insensitive to red. Papilio butterflies may have pentachromatic vision; the most complex color vision system in the animal kingdom has been found in stomatopods with up to 12 spectral receptor types thought to work as multiple dichromatic units. The science of color is sometimes called chromatics, colorimetry, or color science, it includes the study of the perception of color by the human eye and brain, the origin of color in materials, color theory in art, the physics of electromagnetic radiation in the visible range. Electromagnetic radiation is characterized by its intensity; when the wavelength is within the visible spectrum, it is known as "visible light". Most light sources emit light at many different wavelengths.
Although the spectrum of light arriving at the eye from a given direction determines the color sensation in that direction, there are many more possible spectral combinations than color sensations. In fact, one may formally define a color as a class of spectra that give rise to the same color sensation, although such classes would vary among different species, to a lesser extent among individuals within the same species. In each such class the members are called metamers of the color in question; the familiar colors of the rainbow in the spectrum—named using the Latin word for appearance or apparition by Isaac Newton in 1671—include all those colors that can be produced by visible light of a single wavelength only, the pure spectral or monochromatic colors. The table at right shows approximate wavelengths for various pure spectral colors; the wavelengths listed are as measured in vacuum. The color table should not be interpreted as a definitive list—the pure spectral colors form a continuous spectrum, how it is divided into distinct colors linguistically is a matter of culture and historical contingency.
A common list identifies six main bands: red, yellow, green and violet. Newton's conception included a seventh color, between blue and violet, it is possible that what Newton referred to as blue is nearer to what today is known as cyan, that indigo was the dark blue of the indigo dye, being imported at the time. The intensity of a spectral color, relative to the context in which it is viewed, may alter its perception considerably; the color of an object depends on both the physics of the object in its environment and the characteristics of the perceiving eye and brain. Physically, objects can be said to have the color of the light leaving their surfaces, which depends on the spectrum of the incident illumination and the reflectance properties of the surface, as well as on the angles of illumination and viewing; some objects not only reflect light, but transmit light or emit light themselves, which contributes to the color. A viewer's perception of the object's color depends not only on the spectrum of the light leaving its surface, but on a host of contextual cues, so that color differences between objects can be discerned independent of the lighting spectrum, viewing angle, etc.
This effect is known as color constancy. Some generalizations of the physics can be drawn, neglecting perceptual effects for now: Light arriving at an opaque surface is either reflected "specularly", scattered, or absorbed – or some combination of these. Opaque objects that do not reflect specularly have their color determined by which wavelengths of light they scatter strongly. If objects scatter all wavelengths with r