The combination of complementary colors has long fascinated both artists and scientists alike. Complementary colors are pairs of colors that sit opposite each other on the color wheel. Some classic examples of complementary color pairs include red and green, blue and orange, and yellow and purple. When complementary colors are mixed together, they have the unique effect of neutralizing each other to produce various shades of gray or brown. This blending of distinct colors into a neutral tone is one of the most interesting phenomena in color theory. In this article, we’ll explore the specifics of how and why complementary colors make brown when combined.
What are complementary colors?
The basic color wheel consists of 12 distinct hues – 3 primary colors (red, yellow, and blue), 3 secondary colors (orange, green, and purple) and 6 tertiary colors in between. The primary colors form the spokes of the color wheel, with the secondaries located halfway between each primary pair, and the tertiaries spaced evenly between.
Complementary colors are any two colors located directly across from each other on the standard 12-part color wheel. Some examples include:
| Red | Green |
| Yellow | Purple |
| Blue | Orange |
These complementary pairs contain hues from opposite sides of the color spectrum that create strong visual contrast when placed next to each other. However, when mixed together, they oddly neutralize into shades of brown or gray.
Why do complementary colors neutralize each other?
On the light spectrum, complementary colors contain wavelengths that are complete opposites. When complementary light waves mix and overlap, they effectively cancel each other out. This cancellation eliminates the intensity of each hue, leaving behind a neutral shade.
For example, orange paint contains wavelengths of red light, while blue paint contains wavelengths of blue light. When orange and blue mix, the red and blue wavelengths collide and cancel out. With the bright wavelengths removed, the mixture becomes brown or gray. This same principle applies to all sets of complementary colors.
At the particle level, this cancellation occurs because each complementary color absorbs the wavelength of light that its opposite emits. The blue pigment particles absorb the red wavelengths from the orange pigment, and the orange particles absorb the blue wavelengths from the blue pigment. All bright wavelengths get soaked up, leaving just the neutral tones behind.
The color brown
Brown is not technically part of the visible light spectrum. Rather than containing one distinct wavelength, brown contains a combination of multiple different wavelengths. Brown can be made by mixing complementary colors because it is composed of the portions of the spectrum that are left over once the pairs of opposites cancel out.
For example, when green and red light mix, the green absorbs the long red wavelengths and the red absorbs the short green wavelengths. The mid-range wavelengths that are not absorbed by either color emerge as brown. Brown sits as the dull midpoint between vivid complementary colors.
Shades of brown span a wide range depending on the hues being mixed. Mixing bright complements like red and green makes a darker, richer brown. Mixing less saturated complements like yellow and purple creates a soft, light brown. Tweaking the ratio of the colors also impacts the exact tone. But no matter the colors involved, blending any complements moves the result toward a brownish intermediate.
The physics of light absorption
The key physics at work in the blending of complementary colors is the absorption of light wavelengths. Pigment particles contain certain atoms that selectively absorb specific wavelengths of visible light. When light shines on a pigmented surface, the atoms of that pigment absorb the wavelengths that match their own resonant frequencies. The selectively absorbed wavelengths are removed from the reflected light, which is why we perceive those colors on the surface.
For example, chlorophyll, the pigment in most plants, contains bonded carbon and nitrogen atoms. The electrons in these atoms resonate at frequencies associated with red and blue light. As a result, chlorophyll absorbs red and blue photons when white light shines on it. The reflected light lacking red and blue wavelengths appears green.
By absorbing certain incoming wavelengths, pigment particles literally subtract those colors from the visible spectrum. Complementary pigments have atoms that absorb opposite wavelengths. When combined, the atoms in the two pigments absorb all the wavelengths of each other, leaving behind only the overlapping tones that neither absorbs strongly. This creates the muddy browns and grays that define color neutralization.
The art of color mixing
Mastering color combination is a key skill for artists in any visual medium. Understanding complementary colors provides insight into the diverse array of browns achievable through blending. Many paintings make liberal use of blended neutrals to depict realistic shadows, contours, and textures.
One common technique when working with complements is to start with a dominant color and add small amounts of its complement. This allows the artist to reach ideal tones while retaining some of the original hue. For example, a painter may start with a reddish brown base and tweak it with hints of green glaze. Even a touch of the complement neutralizes the tone. Learning the complement pairs and their mixing potentials takes color mastery to a new level.
Artists must also consider the effect on lightness when blending complements. Mixing a darker color like navy blue with a lighter color like peach can make the resulting brown feel murky and imbalanced. Adjusting for lightness often improves color harmony in blended neutrals. Thoughtful color mixing requires understanding both complementarity and lightness relationships.
The color wheel’s spin-off concepts
The simple color wheel and notion of complements provide the foundation for several more intricate color frameworks. These include:
Split Complements: This scheme uses one color plus the two colors adjacent to its complement. For example, blue, yellow-orange, and red-orange. This provides a more nuanced variation than straight complements.
Triadic colors: These are three colors spaced evenly around the color wheel. Mixing triadic colors (like red, yellow, and blue) creates a highly desaturated near-neutral.
Tetradic colors: Tetrads use four colors spaced evenly around the wheel. Mixing all four colors dampens the intensity even more than triads.
Analogous colors: Analogous colors sit right next to each other on the wheel. They heavily overlap in hue, so mixing them creates low-contrast browns.
Master painters combine complements, triads, tetrads, and more to generate the infinite array of practical browns used in shading and realism. A color genius understands the full scope of neutralizing interactions.
The math of color mixing
In color theory, the combination of paints and pigments can be described mathematically through the physics of light absorption. When two colors with different absorption spectra mix together, their light-absorbing properties combine additively based on the relative quantities of each pigment.
For example, say color A absorbs 30% of red light, and color B absorbs 40% of green light. When one part color A is mixed with two parts color B, the combined absorption is:
30% red (from color A)
+ 80% green (40% from color B x 2 parts color B)
= 110% total absorption
The total absorption exceeds 100% because the red-absorbing and green-absorbing pigments stack their actions. This overlap is what removes enough wavelengths to make brown. Adjusting the ratios of the complements changes the tone of the resulting brown.
Color scientists have quantified the precise absorption characteristics of different pigments. This allows the calculation of any conceivable color mixture using the principles of additive light absorption. Computers leverage such color math to blend digital pigments and predict the exact neutral tones that will arise.
Pigment blending in nature
The color-neutralizing phenomenon seen with complements also occurs in the natural world. Many plants, animals, and minerals exhibit brownish or muted hues due to the blended pigments within them.
For example:
– Feathers contain both red and green pigments that mix to brownish tones in many birds.
– Overlapping black and orange pigments in mammals’ coats make earthy brown fur.
– Dirt’s heterogeneous mixture of plant and rock pigments blend to muddy browns.
– Autumn leaves shifting from green to red turn brown during the color transition.
– Some algae and fungi naturally contain both blue and yellow pigments that neutralize to olive and tan shades.
Nature provided the original inspiration for color theory principles. The natural blending of complement-like pigments generates the range of neutral browns important for camouflage, soil health, and seasonal color variation.
Uses of blended brown pigments
Beyond the physics, mixing complementary colors to create browns has many practical purposes and applications. Some examples include:
– Neutral brown paints for wall colors, furniture, crafts
– Makeup and cosmetics shades for contours and shadows
– Dyes for fabrics, leathers, yarns
– Photography developing chemicals
– Food coloring for chocolates, beverages, baked goods
– Pharmaceutical capsules, tablets, salves
– Industrial chemical indicators
By harnessing color neutralization, manufacturers can economically produce an endless diversity of brown and earth-toned products. The brownish dyes, inks, foods, medicines, and more derived from complementary mixes permeate everyday life.
Conclusion
When combined, complementary colors neutralize each other’s brightness and vibrancy to produce brown. This stems from the physics of light absorption and wavelength cancellation. Complementary pigment particles literally soak up the wavelengths that their opposite emits. Mixing complements removes all distinct wavelengths, leaving only the overlapping common tones of brown and gray. Mastering the interactions of complements gives artists and designers invaluable control over neutrals. Beyond its scientific intrigue and artistic utility, the neutralization phenomenon also generates the muted browns found ubiquitously in nature. So whether on canvas or forest floor, complementary colors blended together will always deliver some shade of brown.
