Editing Purple (section)

=== Optics ===
The meanings of the color terms violet and purple varies even among native speakers of English, for example between United Kingdom and United States.<ref name="Computational evidence of first ext">{{cite journal |last1=Tager |first1=A. |last2=Kirchner |first2=E. |last3=Fedorovskaya |first3=E. |title=Computational evidence of first extensive usage of violet in the 1860s |journal=Color Research & Application |date=2021 |volume=46 |issue=5 |pages=961–977 |doi=10.1002/col.22638|s2cid=233671776 }}</ref> Optics research on purple and violet contains contributions of authors from different countries and different native languages, it is likely to be inconsistent in the use and meaning of the two colors.

According to some speakers/authors of English, purple, unlike violet, is not one of the colors of the [[visible spectrum]].<ref name="StClair">{{Cite book|title=The Secret Lives of Colour|last=St. Clair|first=Kassia|publisher=John Murray|year=2016|isbn=978-1-4736-3081-9|location=London|page=159|oclc=936144129}}</ref> It was not one of the colors of the rainbow identified by [[Isaac Newton]]. According to some authors, purple does not have its own [[wavelength]] of light. For this reason, it is sometimes called a ''[[Spectral color#Extra-spectral colors|non-spectral color]]''. According to some speakers of English, purple is simply a combination, in various proportions, of two primary colors, red and blue.<ref>{{cite journal |last1=Matschi |first1=M. |title=Color terms in English: Onomasiological and Semasiological aspects |journal=Onomasiology Online |date=2005 |volume=5 |pages=56–139 }}</ref> According to other speakers of English, the same range of colors is called violet.<ref name="The ANLAB colour system and the dye">{{cite journal|last1=Cooper|first1=A.C.|last2=McLaren|first2=K.|date=1973|title=The ANLAB colour system and the dyer's variables of "shade" and strength|journal=Journal of the Society of Dyers and Colourists|volume=89|issue=2|pages=41–45|doi=10.1111/j.1478-4408.1973.tb03128.x}}</ref>

In some textbooks of [[color theory]], and depending on the geographical-cultural origin of the author, a "purple" is defined as any [[Spectral color#Extra-spectral colors|non-spectral color]] between [[Violet (color)|violet]] and red (excluding violet and red themselves).<ref name="gilbert222" /> In that case, the [[spectral color]] violet would not be shades of purple. For other speakers of English, these colors are shades of purple.

In the traditional color wheel long used by painters, purple is placed between crimson and violet.<ref>See ''Oxford English Dictionary'' definition</ref> However, also here there is much variation in color terminology depending on cultural background of the painters and authors, and sometimes the term violet is used and placed in between red and blue on the traditional color wheel. In a slightly different variation, on the [[HSV color space|color wheel]], purple is placed between magenta and violet. This shade is sometimes called electric purple (see [[shades of purple]]).<ref>Lanier F. (editor) ''The Rainbow Book'' Berkeley, California: Shambhala Publications and The Fine Arts Museums of San Francisco (1976) (Handbook for the Summer 1976 exhibition ''The Rainbow Art Show'' which took place primarily at the [[De Young Museum]] but also at other museums) Portfolio of color wheels by famous theoreticians—see Rood color wheel (1879) p. 93</ref>

In the [[RGB color model]], named for the colors red, green, and blue, used to create all the colors on a computer screen or television, the range of purples is created by mixing red and blue light of different intensities on a black screen. The standard [[HTML]] color purple is created by red and blue light of equal intensity, at a brightness that is between full power and darkness.

In color printing, purple is sometimes represented by the color [[magenta]] mixed with cyan and/or black, or sometimes by mixing magenta with red or blue. It can also be created by mixing just red and blue alone, but in that case the purple is less bright, with lower
saturation or intensity.  A less bright purple can also be created with light or paint by adding a certain quantity of the third primary color (green for light or yellow for pigment).