Editing Primary color (section)

== Traditional red, yellow, and blue primary colors as a subtractive system ==
[[File:Color Mixing Guide cover and plates.jpg|thumb|upright=1.4|Color Mixing Guide, John L. King 1925, cover and plates describing yellow, red, and blue color mixing]]
[[File:Farbkreis Itten 1961.svg|thumb|upright=0.8|A representation of [[Johannes Itten]]'s color wheel showing his red, yellow, and blue as primary colors within the central equilateral triangle<ref name="itten1961"/>]]

Color theorists since the seventeenth century, and many artists and designers since that time, have taken red, yellow, and blue to be the primary colors (see [[#Red,_yellow,_and_blue_as_primary_colors|history]] below). This RYB system, in "traditional color theory", is often used to order and compare colors, and sometimes proposed as a system of mixing pigments to get a wide range of, or "all", colors.<ref name="o'connor">
O'Connor, Zena. "Traditional colour theory: A review." Color Research & Application, 8 January 2021.
</ref>
O'Connor describes the role of RYB primaries in traditional color theory:<ref>
{{cite book | title=Encyclopedia of Color Science and Technology – Living Edition |publisher=Springer |chapter-url=https://link.springer.com/referenceworkentry/10.1007/978-3-642-27851-8_453-1 |access-date=6 June 2021 | author = Zena O’Connor | chapter = RYB Color|year=2021 |pages=1–4 |doi=10.1007/978-3-642-27851-8_453-1 |isbn=978-3-642-27851-8 |s2cid=241083080 }}
</ref>
{{blockquote|A cornerstone component of traditional color theory, the RYB conceptual color model underpins the notion that the creation of an exhaustive gamut of color nuances occurs via intermixture of red, yellow, and blue pigments, especially when applied in conjunction with white and black pigment color. In the literature relating to traditional color theory and RYB color, red, yellow, and blue are often referred to as primary colors and represent exemplar hues rather than specific hues that are more pure, unique, or proprietary variants of these hues.}}

Traditional color theory is based on experience with pigments, more than on the science of light. In 1920, Snow and Froehlich explained:<ref>{{cite book | author=Bonnie E. Snow and Hugo B. Froehlich |title=The Theory and Practice of Color |date=1920 |publisher=Prang |page=14 |url=https://books.google.com/books?id=-_kjAAAAMAAJ&q=snow+%22the+theory+and+practice+of+color%22 |access-date=12 June 2021}}</ref>
{{blockquote
|text=It does not matter to the makers of dyes if, as the physicist says, red light and green light in mixture make yellow light, when they find by experiment that red pigment and green pigment in mixture produce gray.  No matter what the spectroscope may demonstrate regarding the combination of yellow rays of light and blue rays of light, the fact remains that yellow pigment mixed with the blue pigment produces green pigment.}}

The widespread adoption of teaching of RYB as primary colors in post-secondary art schools in the twentieth century has been attributed to the influence of the [[Bauhaus]], where [[Johannes Itten]] developed his ideas on color during his time there in the 1920s, and of his book on color<ref>
{{cite journal |last1=Gage |first1=John |title=Colour at the Bahaus |journal=AA Files |date=1982 |issue=2 |pages=50–54 |jstor=29543325 |url=https://www.jstor.org/stable/29543325 |issn=0261-6823}}
</ref><ref>
{{cite journal |last1=Raleigh |first1=Henry P. |title=Johannes Itten and the Background of Modern Art Education |journal=Art Journal |date=1968 |volume=27 |issue=3 |pages=284–302 |doi=10.2307/775089|jstor=775089 }}</ref> published in 1961.<ref name="itten1961">{{cite book |last1=Itten |first1=Johannes |title=The art of color : the subjective experience and objective rationale of color |date=1961 |publisher=Reinhold Pub. Corp |location=New York |isbn=0442240376 |pages=34–37 |quote=By way of introduction to color design, let us develop the 12-hue color circle from the primaries{{snd}} yellow, red, and blue. As we know, a person with normal vision can identify a red that is neither bluish, nor yellowish; a yellow that is neither greenish, nor reddish: and a blue that is neither greenish, nor reddish. In examining each color, it is important to view it against a neutral-gray background.}}
</ref>

In discussing color design for the web, Jason Beaird writes:<ref>{{cite book |last1=Beaird |first1=Jason |title=The Principles of Beautiful Web Design |date=2010 |publisher=SitePoint |isbn=9781457192449 |page=55 |url=https://books.google.com/books?id=FxejBgAAQBAJ&dq=%22traditional+color+theory%22+red+yellow+blue&pg=PA55 |access-date=12 June 2021 }}{{Dead link|date=June 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>
{{blockquote
|text=The reason many digital artists still keep a red, yellow, and blue color wheel handy is because the color schemes and concepts of traditional color theory are based on that model.&nbsp;... Even though I design mostly for the Web—a medium that's displayed in RGB—I still use red, yellow, and blue as the basis for my color selection.  I believe that color combinations created using the red, yellow, and blue color wheel are more aesthetically pleasing, and that good design is about aesthetics.}}

As with any system of real primaries, not all colors can be mixed from RYB primaries.<ref>
{{cite book
| last1  = Westland
| first1 = Stephen
| title  = Handbook of Visual Display Technology |date=2016
| publisher = Springer International Publishing
| page = 162
| url = https://rd.springer.com/content/pdf/10.1007/978-3-319-14346-0_11.pdf
| access-date = 12 December 2017
| language = en
| doi = 10.1007/978-3-319-14346-0_11
| isbn = 9783319143460
| quote = A common misapprehension is that it is possible to define three color primaries that could create any color by mixture. Unfortunately, the range of reproducible colors (or gamut) for a trichromatic additive (or subtractive) system is limited and is always smaller than the gamut of all the colors possible in the world. However, the gamut is smaller or larger depending upon the choice of primaries. Pragmatically, for additive color mixing the largest gamut is achieved when the primaries are red, green, and blue.
}}
</ref> 
For example, if the blue pigment is a deep [[Prussian blue]], then a muddy desaturated green may be the best that can be had by mixing with yellow.<ref name=stjohn/> To achieve a larger gamut of colors via mixing, the blue and red pigments used in illustrative materials such as the ''Color Mixing Guide'' in the image are often closer to [[peacock blue]] (a [[blue-green]] or [[cyan]]) and [[carmine (color)|carmine]] (or [[crimson]] or [[magenta]]) respectively.<ref name=stjohn>
{{cite journal |last1=St. John |first1=Eugene |title=Some Practical Hints on Presswork |journal=The Inland Printer |date=February 1924 |volume=72 |issue=5 |page=805 |url=https://books.google.com/books?id=nxUhAQAAMAAJ&pg=RA8-PA805 | quote = While Prussian blue and crimson lake are available in three-color work, a broken yellow like Dutch pink is not, unless green and purple values may be sacrificed to obtain black.  So a fourth printing in weak black or gray was added, and the three-color became the four-color process.  At the same time, peacock blue was substituted to a large extent for Prussian blue.&nbsp;... While process yellow may be considered lemon yellow, process red, carmine lake, three-color process blue, Prussian blue, and four-color process blue, peacock blue, many variations are encountered in practice;&nbsp;... Bright reds may be mixed from process red and vermilion, chrome greens from process blue and process yellow, and useful purples from process red and reflex blue.}}
</ref><ref name=raymer>
{{cite book | last1=Raymer | first1=Percy C. | title=Photo-engravers' Hand-book on Etching & Finishing |date=1921 |publisher=Effingham Republican |page=52 |url=https://books.google.com/books?id=R8B_pwhP9tgC&pg=PA73 |access-date=6 June 2021 | quote = The so-called pure 'primary red pigment' (more correctly 'magenta') printed onto white paper absorbs the green light (its complementary) and the pure 'blue primary pigment', which is practically a strong cyan or peacock blue, absorbs the bright orange-red light (its complementary).
}}
</ref><ref name=draftsman>
{{cite book | author=United States Bureau of Naval Personnel | title=Illustrator Draftsman 1 & C | date=1967 | publisher=U.S. GPO | page=82 | url = https://books.google.com/books?id=PzlVzeq0VCUC&pg=PA82 |access-date=6 June 2021 | quote = This is based on the fact that most colors can be approximated from a mixture of the primary colors – red, yellow, and blue. However, in process colors, the red is closer to a magenta than a vermilion, the blue is rather pale and greenish, and only the yellow is the bright, clear shade we usually think of as a primary color.}}
</ref> 
Printers traditionally used inks of such colors, known as "process blue" and "process red", before modern color science and the printing industry converged on the process colors (and names) cyan and magenta<ref name=stjohn/><ref name=draftsman/> RYB is not the same as CMY, nor exactly subtractive, but that there is a range of ways to conceptualize traditional RYB as a subtractive system in the framework of modern color science.

Faber-Castell identifies the following three colors: "Cadmium yellow" (number 107) for yellow, "Phthalo blue" (number 110) for blue and "Deep scarlet red" (number 219) for red, as the closest to primary colors for its Art & Graphic color pencils range. "Cadmium yellow" (number 107) for yellow, "Phthalo blue" (number 110) for blue and "Pale geranium lake" (number 121) for red, are provided as primary colors in its basic 5 color "Albrecht Dürer" watercolor marker set.

=== Mixing pigments in limited palettes ===
{{main|Paint mixing}}
[[File:Självporträtt av Anders Zorn 1896.jpg|thumb|upright|An 1896 self-portrait by [[Anders Zorn]] clearly showing a four-pigment palette of what are thought to be white, [[yellow ochre]], [[vermillion]], and black pigments<ref>{{cite book |last1=Harrison |first1=Birge |title=Landscape Painting |date=1909 |publisher=Scribbner |page=118 |url=https://books.google.com/books?id=bCdNRQ20kTYC |language=en |quote=The expert cannot be bothered with useless pigments. He selects the few that are really essential and throws aside the rest as useless lumber. The distinguished Swedish artist, Zorn, uses but two colors—vermilion and yellow ochre; his two other pigments black and white, being the negation of color. With this palette, simple to the point of poverty, he nevertheless finds it possible to paint an immense variety of landscape and figure subjects.}}</ref>]]

The first known use of red, yellow, and blue as "simple" or "primary" colors, by [[Chalcidius]], ca. AD 300, was possibly based on the art of paint mixing.<ref>Kuehni, Rolf G. "Development of the idea of simple colors in the 16th and early 17th centuries". ''Color Research & Application'' 32.2 (2007): 92–99.</ref>

Mixing pigments for the purpose of creating realistic paintings with diverse color gamuts is known to have been practiced at least since [[Ancient Greece]] (see [[#History|history section]]). The identity of a/the set of minimal pigments to mix diverse gamuts has long been the subject of speculation by theorists whose claims have changed over time, for example, Pliny's white, black, one or another red, and "sil", which might have been yellow or blue; Robert Boyle's white, black, red, yellow, and blue; and variations with more or fewer "primary" color or pigments. Some writers and artists have found these schemes difficult to reconcile with the actual practice of painting.<ref name=gage_apelles>{{cite book |last1=Gage |first1=John |title=Color and Culture: Practice and Meaning from Antiquity to Abstraction |year=1999 |publisher=University of California Press |isbn=978-0-520-22225-0 |url=https://books.google.com/books?id=oq_GtjmoTNgC&q=color+and+culture&pg=PA7 |language=en}}</ref>{{rp|29–38}} Nonetheless, it has long been known that limited palettes consisting of a small set of pigments are sufficient to mix a diverse gamut of colors.<ref name="Boyle1664">{{cite book |last1=Boyle |first1=Robert |date=1664 | publisher=Henry Herringman|title=Experiments and Considerations touching Colours |page=220 |url=http://www.gutenberg.org/ebooks/14504 |quote=But I think I may easily be excus'd (though I do not altogether pass it by) if I restrain my self to the making of a Transient mention of some few of their Practices about this matter; and that only so far forth, as may warrant me to observe to you, that there are but few Simple and Primary Colours (if I may so call them) from whose Various Compositions all the rest do as it were Result. For though Painters can imitate the Hues (though not always the Splendor) of those almost Numberless differing Colours that are to be met with in the Works of Nature, and of Art, I have not yet found, that to exhibit this strange Variety they need imploy any more than White, and Black, and Red, and Blew, and Yellow; these five, Variously Compounded, and (if I may so speak) Decompounded, being sufficient to exhibit a Variety and Number of Colours, such, as those that are altogether Strangers to the Painters Pallets, can hardly imagine.}}</ref><ref>{{cite book |last1=Rood |first1=Ogden |title=Modern chromatics; students' text-book of color, with applications to art and industry. |date=1973 |publisher=Van Nostrand Reinhold Co |location=New York |isbn=0-442-27028-3 |pages=108|url=http://lcweb2.loc.gov/service/gdc/scd0001/2010/20100701001mo//20100701001mo.pdf |archive-url=https://web.archive.org/web/20170118111614/http://lcweb2.loc.gov/service/gdc/scd0001/2010/20100701001mo/20100701001mo.pdf |archive-date=2017-01-18 |url-status=live |quote=It is well known to painters that approximate representations of all colours can be produced by the use of very few pigments. Three pigments or coloured powders will suffice, a red, yellow, and a blue; for example, crimson lake, gamboge, and Prussian blue. The red and yellow mingled in various proportions will furnish different shades of orange and orange-yellow; the blue and yellow will give a great variety of greens; the red and blue all the purple and violet hues. There have been instances of painters in water-colours who used only these three pigments, adding lampblack for the purpose of darkening them and obtaining the browns and greys.}}</ref><ref>{{cite journal
| last1   = Nyholm
| first1  = Arvid
| title   = Anders Zorn: The Artist and the Man
| journal = Fine Arts Journal
| date    = 1914
| volume  = 31
| issue   = 4
| pages   = 469–481
| doi     = 10.2307/25587278
| jstor   = 25587278
| quote   = It is true that Zorn uses only a very limited palette, especially when he paints indoors, when he considers that black, white, red and yellow should be enough for all ordinary purposes, except when a very decided color is present, as, for instance, a light blue or a positive green in a drapery.
}}</ref><ref>{{cite book |last1=Munsell |first1=Albert H. |title=A Color Notation |date=1907 |url=http://www.gutenberg.org/files/26054/26054-h/26054-h.htm |quote=Studio and school-room practice still cling to the discredited theory, claiming that, if it fails to describe our color sensations, yet it may be called practically true of pigments, because a red, yellow, and blue pigment suffice to imitate most natural colors.}}</ref><ref>{{cite book |last1=Lintott |first1=E. Barnard |title=The Art of Water Colour Painting |date=1926 |publisher=C. Scribner's Sons |page=25 |url=https://books.google.com/books?id=ycNNAAAAYAAJ |language=en |quote=For a young student there cannot be a better way of entering upon the study of water colour than by rigorously banishing all but two colours from his palette. It is the best and surest way to the study of full colour. The colours should be a cold and warm one; cobalt blue and warm sienna—or Prussian blue and burnt sienna—are two combinations which lend themselves to a great variety of treatment.}}</ref>

The set of pigments available to mix diverse gamuts of color (in various media such as [[oil paint|oil]], [[watercolor painting|watercolor]], [[acrylic paint|acrylic]], [[gouache]], and [[pastel]]) is large and has changed throughout history.<ref>{{cite book |last1=Eastaugh |first1=Nicholas |last2=Walsh |first2=Valentine |last3=Chaplin |first3=Tracey |last4=Siddall |first4=Ruth |title=Pigment Compendium: A Dictionary of Historical Pigments |date=30 March 2007 |publisher=Routledge |isbn=978-1-136-37386-2 |language=en}}</ref><ref>{{cite book |last1=Ball |first1=Philip |title=Bright earth : art and the invention of color |year=2002 |orig-year=2001 |publisher=Farrar, Straus and Giroux |location=New York |isbn=0226036286 |edition=1st American}}</ref> There is no consensus on a specific set of pigments that are considered primary colors{{snd}} the choice of pigments depends entirely on the artist's subjective preference of subject and style of art, as well as material considerations like [[lightfastness]] and mixing behavior.<ref>{{cite web |last1=MacEvoy |first1=Bruce |title=handprint : learning color through paints |url=https://www.handprint.com/HP/WCL/intstud.html |website=www.handprint.com |access-date=27 April 2021}}</ref> A variety of limited palettes have been employed by artists for their work.<ref>{{cite web |last1=MacEvoy |first1=Bruce |title=palette paintings |url=https://www.handprint.com/HP/WCL/paletfs.html |website=www.handprint.com |access-date=3 February 2021}}</ref><ref>{{cite book |last1=Gurney |first1=James |title=Color and Light: A Guide for the Realist Painter |date=2010 |publisher=Andrews McMeel Publishing |location=Kansas City, Missouri |isbn=978-0-7407-9771-2 |page=104 |url=https://books.google.com/books?id=MvddjqkQy9UC&q=%22limited%20palette%22 |language=en}}</ref>

The color of light (i.e., the spectral power distribution) reflected from illuminated surfaces coated in paint mixes is not well approximated by a subtractive or additive mixing model.<ref>{{cite journal |last1=Haase |first1=Chet S. |last2=Meyer |first2=Gary W. |title=Modeling pigmented materials for realistic image synthesis |journal=ACM Transactions on Graphics |date=1 October 1992 |volume=11 |issue=4 |pages=305–335 |doi=10.1145/146443.146452 |s2cid=6890110 |quote=Section 2 develops some of the significant differences in additive and subtractive color mixing and discusses the need for different mixing theory for pigmented materials.|doi-access=free }}</ref> Color predictions that incorporate light scattering effects of pigment particles and paint layer thickness require approaches based on the [[Kubelka–Munk theory|Kubelka–Munk equations]],<ref>{{cite journal |last1=Lu |first1=Jingwan |last2=DiVerdi |first2=Stephen |last3=Chen |first3=Willa A. |last4=Barnes |first4=Connelly |last5=Finkelstein |first5=Adam |title=RealPigment: paint compositing by example |journal=Proceedings of the Workshop on Non-Photorealistic Animation and Rendering |date=8 August 2014 |pages=21–30 |doi=10.1145/2630397.2630401|s2cid=1415118 }}</ref> but even such approaches are not expected to predict the color of paint mixtures precisely due to inherent limitations.<ref>{{cite book |last1=Curtis |first1=Cassidy J. |last2=Anderson |first2=Sean E. |last3=Seims |first3=Joshua E. |last4=Fleischer |first4=Kurt W. |last5=Salesin |first5=David H. |title=Proceedings of the 24th annual conference on Computer graphics and interactive techniques - SIGGRAPH '97 |chapter=Computer-generated watercolor |date=1997 |pages=421–430 |doi=10.1145/258734.258896 |isbn=0897918967 |s2cid=3051452 |quote=In summary, the fact that the KM model appears to work so well could actually be considered quite surprising, given the number of basic assumptions of the model violated by watercolor. We suspect that while the results of the model are probably not very physically accurate, they at least provide very plausible physical approximations, which appear quite adequate for many applications.}}</ref> Artists typically rely on mixing experience and "recipes"<ref>{{cite book |last1=Powell |first1=William F. |title=1,500 Color Mixing Recipes for Oil, Acrylic & Watercolor: Achieve Precise Color when Painting Landscapes, Portraits, Still Lifes, and More |date=August 2012 |publisher=Walter Foster Publishing |isbn=978-1-60058-283-7 |url=https://books.google.com/books?id=RsGJFZs5yyIC |language=en}}</ref><ref>{{cite web |last1=MacEvoy |first1=Bruce |title=handprint : basic mixing method |url=https://www.handprint.com/HP/WCL/mix.html |website=www.handprint.com}}</ref> to mix desired colors from a small initial set of primaries and do not use mathematical modeling.

MacEvoy explains why artists often chose a palette closer to RYB than to CMY:<ref>{{cite web |last1=MacEvoy |first1=Bruce |title=imaginary or imperfect primaries |url=http://www.handprint.com/HP/WCL/color6.html#imaginary |website=handprint.com |access-date=13 June 2021}}</ref>{{unreliable source?|date=December 2024}} 
{{blockquote
|text=Because the 'optimal' pigments in practice produce unsatisfactory mixtures; because the alternative selections are less granulating, more transparent, and mix darker values; and because visual preferences have demanded relatively saturated yellow to red mixtures, obtained at the expense of relatively dull green and purple mixtures. Artists jettisoned 'theory' to obtain the best color mixtures in practice.}}
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