The primary colors are the set of colors that can be combined to create all other colors in a given color space. There are two common sets of primary colors used in art, design, and optics: RGB (red, green, and blue) and RYB (red, yellow, and blue). The RGB and RYB color models use different primary colors based on different theories of color vision and color mixing. This leads to an ongoing debate over which set of primaries is the “real” or “true” set of primary colors.
RGB Primary Colors
The RGB color model uses red, green, and blue as the three primary colors. This model is based on the Young–Helmholtz theory of trichromatic color vision, which states that the human eye contains three types of color receptors that respond to red, green, and blue light.
The RGB primaries align with the long-, medium- and short-wavelength sensitivity of the light receptors in our eyes. When red, green, and blue light are mixed together in different proportions, our eyes perceive the entire spectrum of colors. For example, red and green light combined make yellow. All other colors can be made by mixing the RGB primary colors together in different ratios.
The RGB color model is used for color video and computer displays, which create colors by emitting different levels of red, green, and blue light. RGB is also used in digital imaging systems like cameras and scanners, which use RGB color filters to record color information.
RYB Primary Colors
The RYB color model uses red, yellow, and blue as the primary colors. This is the traditional set of primary colors used by artists for painting and drawing. The RYB primary colors provide pure pigments that when mixed create a good range of secondary and tertiary colors for art and design.
The RYB color model is rooted in the artistic color theory of painters and photographers. While RGB aligns with the physiology of human vision, RYB is based on the history of pigments and dyes used in art media. Early painters created red, yellow, and blue pigments from mineral and plant sources that could not be mixed further. These became the basic colors for mixing other hues.
For example, red and yellow ochre pigments were used to mix orange. Blue and yellow mixed together make green. Combining all three primaries at different ratios produces browns, neutrals, and near-blacks. This is why RYB provides an effective basis for mixing colors with paints, inks, pastels, and other subtractive color media.
Key Differences Between RGB and RYB
While both RGB and RYB provide primary colors that can be mixed to form other hues, there are important differences between the two color models:
| RGB | RYB |
|---|---|
| Based on the physiology of human vision and color receptors in the eyes | Based on historical artistic color theory and pigment mixing |
| Used for light-emitting displays and digital imaging | Used for traditional paints, inks, and other art media |
| Primary colors are red, green, and blue | Primary colors are red, yellow, and blue |
| Mixing pure RGB primaries makes white | Mixing RYB primaries makes black or brown |
Some key differences emerge from the different primary colors chosen by each model:
– The RGB red, green, and blue are pure spectral colors with specific wavelengths of light. RYB red, yellow, and blue are idealized cognitive primaries that don’t correspond to monochromatic light.
– Mixing equi-luminant RGB primaries creates shades of white and lighter grays. Mixing RYB primaries makes darker browns, grays, and blacks.
– The RGB gamut can reproduce more saturated greens, cyans, and magentas. RYB can directly mix more natural hues but has a smaller total gamut.
– RGB can reproduce any visible color by adding light. RYB is limited by the pigments available but useful for subtractive mixing.
So while both models provide primary colors that can be combined to create new hues, the specific primaries differ based on the color mixing theory and the intended use.
Are RGB or RYB the “True” Primaries?
Given the different characteristics and uses of the RGB and RYB primary colors, is one set the “true” or “real” primaries? There are good arguments on both sides of this debate:
The case for RGB:
– RGB aligns with the physical structure of human vision, with primaries matched to the eye’s receptors. This makes RGB scientifically valid as a model of color vision.
– RGB can reproduce a wider gamut of colors, including pure spectral wavelengths. All visible colors can be matched using RGB primaries.
– RGB is used in digital displays and imaging, which increasingly dominate color reproduction technology.
The case for RYB:
– RYB provides pure pigments and practical mixing abilities. While not spectral, RYB primaries effectively create good mixtures for paints, inks, etc.
– RYB has a long artistic history and tradition. The primaries map to pigments used by artists and painters for centuries.
– Many artistic concepts like color theory and the color wheel are based on RYB color relationships and mixing.
Overall there is no definitive answer — both RGB and RYB have merits as primary color systems. RGB is scientifically and technologically superior at reproducing color, but RYB provides a practical model for subtractive color mixing.
For digital media and displays, RGB is the unambiguous standard. But RYB remains useful for artistic applications where pure pigment mixing is needed. Both color models help illustrate the fundamentals of color theory and perception.
Conclusion
The debate over RGB and RYB primary colors relates to differences between additive and subtractive color mixing. RGB is an additive model based on light emission, while RYB is associated with subtractive pigment mixing. Neither is inherently “right or wrong” — they are just useful for different applications.
RGB is the primary model for digital color and aligns with human vision, allowing a wide color gamut. RYB provides traditional pure pigments for artists to practically mix real paints and inks. Both reveal important aspects of color theory. The “real” primary colors are perhaps best seen as the combination of RGB and RYB — red, green, blue, and yellow. Together these four primaries encompass both major color mixing domains.
So in summary:
– RGB and RYB use different primary color sets based on different models of color mixing.
– RGB is better for emitting colors with light. RYB is optimal for mixing pigmented paints and dyes.
– There is merit to both systems – RGB for digital color, RYB for practical use in the arts.
– Neither RGB nor RYB can be considered the one “true” set of primaries. Each is useful in its intended application.
