Editing Color theory (section)

=== Split primary palette ===
The split-primary palette is a color-wheel model that relies on misconceptions to attempt to explain the unsatisfactory results produced when mixing the traditional primary colors, red, yellow, and blue.

Painters have long considered red, yellow, and blue to be primary colors. In practice, however, some of the mixtures produced from these colors lack [[Colorfulness|chromatic intensity]]. Rather than adopt a [[CMY color model|more effective set of primary colors]],<ref>{{cite web |last1=Baird |first1=Christopher S. |title=Associate Professor of Physics |url=https://www.wtamu.edu/~cbaird/sq/2015/01/22/why-are-red-yellow-and-blue-the-primary-colors-in-painting-but-computer-screens-use-red-green-and-blue/ |website=Science Questions with Surprising Answers |publisher=West Texas A&M University |access-date=12 June 2024}}</ref> proponents of split-primary theory explain this lack of chroma by the purported presence of impurities, small amounts of other colors in the paints, or biases away from the ideal primary toward one or the other of the adjacent colors. Every red paint, for example, is said to be tainted with, or biased toward, either blue or yellow, every blue paint toward either red or green, and every yellow toward either green or orange. These biases are said to result in mixtures that contain sets of [[complementary colors]], darkening the resulting color. To obtain vivid mixed colors, according to split-primary theory, it is necessary to employ two primary colors whose biases both fall in the direction, on the color wheel, of the color to be mixed, combining, for example, green-biased blue and green-biased yellow to make bright green. Based on this reasoning, proponents of split-primary theory conclude that two versions of each primary color, often called "cool" and "warm," are needed in order to mix a wide [[gamut]] of high-chroma colors.<ref>{{cite web |last1=Kemp |first1=Will |title=The Hidden Hues of Colour Mixing |url=https://willkempartschool.com/the-hidden-secret-of-colour-mixing/ |website=willkempartschool.com |date=27 August 2011 |publisher=Will Kemp Art School |access-date=15 October 2023}}</ref><ref>{{cite web |last1=Short |first1=Susie |title=Working with a Split Primary Color Palette |url=https://danielsmith.com/artists/insights/susie-short-working-with-a-split-primary-color-palette/ |website=danielsmith.com |date=21 July 2022 |publisher=Daniel Smith |access-date=15 October 2023}}</ref>

In fact, the perceived bias of colors is not due to impurity. Rather, the appearance of any given colorant is inherent to its chemical and physical properties, and its purity unrelated to whether it conforms to our arbitrary conception of an ideal hue. Moreover, the identity of gamut-optimizing primary colors is determined by the physiology of [[Trichromacy|human color vision]]. Although no set of three primary paints can be mixed to obtain the complete color gamut perceived by humans, red, yellow, and blue are a poor choice if high-chroma mixtures are desired. This is because painting is a [[subtractive color]] process, for which red and blue are secondary, not primary, colors.

Although flawed in principle,<ref>{{cite web |last1=Lucariello |first1=Joan |last2=Naff |first2=David |title=How Do I Get My Students Over Their Alternative Conceptions (Misconceptions) for Learning? Applications of Psychological Science to Teaching and Learning modules |url=https://www.apa.org/education-career/k12/misconceptions |website=APA.org |publisher=American Psychological Association |access-date=12 August 2024}}</ref> the split-primary system can be successful in practice, because the recommended blue-biased red and green-biased blue positions are often filled by near approximations of magenta and cyan, respectively, while orange-biased red and violet-biased blue serve as secondary colors, tending to further widen the mixable gamut.

This system is in effect a simplified version of Newton's geometrical rule that colors closer together on the hue circle will produce more vibrant mixtures.  A mixture produced from two primary colors, however, will be much more highly saturated than one produced from two secondary colors, even though the pairs are the same distance apart on the hue circle, revealing the limitations of the circular model in the prediction of color-mixing results. For example, a mixture of magenta and cyan inks or paints will produce vivid blues and violets, whereas a mixture of red and blue inks or paints will produce darkened violets and purples, even though the angular distance separating magenta and cyan is the same as that separating red and blue.