In some societies, color terminology are or were used in racial classifications. They have been used both popularly, as skin color is one of the most obvious physical traits of humans, and in earlier theories, which attempted to provide a rigorous definition of race. Although modern science has disqualified such attempts of classification, considered as racist pseudo-science, they have remained popular ways of depicting human variations. Scientific racism theories themselves progressively substituted other traits instead of human skin tone in their attempts to classify, in particular through the use of craniometry and others disciplines of physical anthropology.

Other scientists were more cautious about such categorisation, and Charles Darwin argued that the number of categories, or in this case the number of different colors, is completely arbitrary and subjective. For example, some claimed three distinct colors, some four, and others have claimed even more. In contrast, Darwin argued that there are gradations, or degrees between the numbers of categories claimed, and not distinct categories, or colors."It may be doubted whether any character can be named which is distinctive of a race and is constant.", Charles Darwin, ''The Descent of Man'' p225 ,
The Mis-portrayal of Darwin as a Racist

Western classifications

Johann Friedrich Blumenbach (1752-1840), one of the founders of scientific racism theories, came up with the five color typology for humans: white (Caucasian), more or less black (Ethiopian), wheat-yellow (Mongolian), cinnamon-brown or flame color (American), brown color (Malay). Blumenbach listed the "races" in a hierarchic order of physical similarities: Caucasian, followed by American, followed by Mongolian, followed by Malaysian, followed by Ethiopian.

The concept of “black” as a metaphor for race was first used at the end of the 17th century when a French doctor named François Bernier (1625-1688), an early proponent of scientific racism, divided up humanity based on facial appearance and body type. He proposed four categories: Europeans, Far Easterners, Lapps, and finally Blacks whom he described as having woolly hair, thick lips, and very white teeth.''The End of Racism'' by Dinesh D'Souza, pg 123, 1995 The first major scientific model was created in 18th century when Carolus Linnaeus recognized four main races: Europeanus which he labeled the white race, Asiatic, which he labeled the yellow race, Americanus, which he labeled the red race, and Africanus, which he labeled the black race.http://www.google.com/search?q=cache:trOZQwTAMhIJ:www.stcl.edu/faculty_pages/faculty_folders/steiner/aal/whiteness.ppt+%2BLinnaeus+black+red+yellow+white+race&hl=en&gl=ca&ct=clnk&cd=3 Linnaeus' protégé, anthropology founder Johann Blumenbach completed the model by adding the brown race, which he called "Malay" for Polynesians and Melanesians of Pacific Islands, and for aborigines of Australia.''The Mismeasure of Man'' by Stephen Jay Gould, pg 402, 1996

According to conservative writer Dinesh D'Souza, "Blumenbach's classification had a lasting influence in part because his categories neatly broke down into familiar tones and colors: white, black, yellow, red, and brown."''The End of Racism'' by Dinesh D'Souza, pg 124, 1995 Gradually the "yellow" and "red" races got lumped together, and the brown race ignored because of its small population, yielding just three races commonly known as mongoloid, caucasoid, and negroid.http://www.lrainc.com/swtaboo/stalkers/jpr01.html The last term is derived from Negro which is the Spanish word for black.http://72.14.205.104/search?q=cache:lDEuCwny0QIJ:www.codesria.org/Links/Publications/bulletin1%2004/keita.pdf++Black+webster+Negro+equivalent+sets&hl=en&gl=ca&ct=clnk&cd=1 Some anthropologists added the brown race back in as an Australoid category (which includes aboriginal peoples of Australia along with various peoples of southeast Asia, especially Melanesia and the Malay Archipelago),http://education.yahoo.com/reference/dictionary/entry/Australoid and viewed it as separate from negroids (often lumping Australoids in with caucasoids) despite the fact that their skin is also dark.http://apologeticspress.org/articles/2007.

Racial classification according to skin color became controversed by anthropologists, who added others, less obvious characteristics, in their attempt to achieve a scientific classification of races. It was later found that skin color depended essentially from the amount of melanin, and could vary widely in the same community. Thus, it could not provide a satisfying way to classify ethnic groups, much less "races." Following World War II and the discredit of such racial classifications, the majority of biologists and anthropologists began to question the concept itself of "race." Thus, ''The Race Question'' statement by the UNESCO, in the 1950s, proposed to substitute the term "ethnic groups" to the concept of "race," arguing that human communities were defined as much by cultural traits (language, religion, etc.) than by biological characteristics (skin color being only one of them, along with blood types, which did not recover previous racial classifications, etc.).

Tone gradations

In some societies people can be sensitive to gradations of skin tone, which may be due to intermarriage or to albinism and which can affect power and prestige. In 1930s Harlem Slang such gradations were described by a tonescale of "high yaller yellow, yaller, high brown, vaseline brown, seal brown, low brown, dark brown".Zora Neale Hurston's - Glossary of Harlem Slang "Tonescale" These terms were sometimes referred to in blues music, both in the words of songs and in the names of performers. In 1920s Georgia, Willie Perryman followed his older brother Rufus in becoming a blues piano player: both were albino Negroes with pale skin, reddish hair and poor eyesight. Rufus was already well established as "Speckled Red", Willie became "Piano Red".''The Blues Collection'' issue 68, ''Piano Red'', Contribution by Tony Russell, 1996 The piano player and guitarist Tampa Red from the same state developed his career in Chicago, Illinois, at that time: his name may have come from his light skin tone, or possibly reddish hair.

More recently such categorisation has been noted in the Caribbean. It is reported that skin tones play an important role in defining how Barbadians view one another, and they use terms such as "brown skin, light skin, fair skin, high brown, red, and mulatto".Barbados - Post Report - eDiplomat An assessment of racism in Trinidad notes people often being described by their skin tone, with the gradations being "HIGH RED – part White, part Black but ‘clearer’ than Brown-skin: HIGH BROWN – More white than Black, light skinned: DOUGLA –part Indian and part Black: LIGHT SKINNED, or CLEAR SKINNED Some Black, but more White: TRINI WHITE – Perhaps not all White, behaves like others but skin White".RACISM IN TRINIDAD (pdf) In Jamaica albinism has been stigmatised, but the albino dancehall singer Yellowman took his stage name in protest against such prejudice and has helped to end this stereotype. The West Indian region uses the term "coolie" for all people of east Indian descent.

China

Huang (yellow) is a common surname, but does not refer to the East Asian race as was popular in Western languages until recently. However, the Yellow Emperor was a legendary founder of China. Yellow is also identified with the "center" cardinal direction (blue-east, red-south, white-west, black-north) while China is known as Zhongguo "central country".

White (白 ''bai'') means "plain" or "free of charge" in many common expressions and was not traditionally used to refer to Europeans or descendants, who were usually identified as "people from the ocean" or some variety of "barbarians" with reddish or pinkish skin colors (eg. Minnan ''ang mo'', "red-haired"). Contemporary Chinese, has, however, adopted Western usage to a large extent. Black (黑 ''hei'') is typically applied to those of African race today. However, the term "black resident" (黑户) also refers to unregistered rural migrants in cities (as in ''black market'').

Names of ethnic minorities sometimes contain colors, not to indicate skin color, but simply for identification, possibly based on traditional clothing or geographical direction.

Red, Black, Blue/Green, White, Flowery (multicolored) Miao (Hmong)

the Bai (literally White) are a sedentary lowland people of Yunnan

Black Bone and White Bone Yi

The Qing dynasty Manchu military were divided into Eight Banners identified by color and with ethnic associations

The Five Races Under One Union theory of national unity can be visualised through an old ROC flag and a variant which emphasised Han administration while de-emphasising the top-to-bottom hierarchy found in the original flag. Red - Han, Yellow - Manchu, Blue - Mongol, White - Hui and Black - Tibetan.