Red and green are two primary colors that are often combined in art, design, and nature. When red pigment is placed over green pigment, the resulting color is a brownish tone. This is due to the optical mixing of the two colors. Optical mixing refers to the blending of colors that happens in the eye and brain when two colors are viewed simultaneously or in close proximity. While red and green are very different hues, combining them results in a muddy, dark color.
How Optical Mixing Works
Human color vision relies on cells in the retina called cone cells. There are three types of cone cells, each responsive to different wavelengths of light. Red light strongly stimulates the L cones, green light the M cones, and blue light the S cones. When multiple colors of light enter the eye, the cone cells are stimulated to varying degrees. The relative stimulation of the L, M and S cones is interpreted by the brain as a particular color.
When red and green light enter the eye together, both the L and M cones are strongly stimulated. However, there is minimal stimulation of the S cones. This combination of L+M stimulation is perceived as a brownish or olive tone. While the red and green colors remain in the light, the mingling of the signals in the eye results in the optical mixture appearing brown.
The Color Wheel
The color wheel is a useful tool for understanding how colors mix together. The color wheel arranges colors by hue in a circular format. Red, yellow, green, blue, purple and their mixtures are placed sequentially around the wheel. Complementary colors exist on opposite sides of the wheel. Red and green are complements, meaning they contain none of the same wavelengths of light.
When complementary colors are optically mixed, they tend to desaturate each other and any mixing results in a more muted, grayish color. For example, red and green form a brown tone, purple and yellow make a tan, and blue and orange mix to a neutralized beige. This muting effect happens because complementaries contain strongly stimulating wavelengths that end up overwhelming the cones when combined.
| Color 1 | Color 2 | Mixed Color |
|---|---|---|
| Red | Green | Brown |
| Purple | Yellow | Tan |
| Blue | Orange | Beige |
Paint Mixing
When working with paints, mixing red and green pigments also produces a brown color. Pigments selectively absorb certain wavelengths of light and reflect others. For example, red pigment absorbs green and blue light, while reflecting red. Green pigment absorbs red and blue, reflecting green.
When the two pigments are blended, the resulting color reflects a combination of the non-absorbed wavelengths. Most of the green from the green pigment and some red from the red pigment are reflected. As blue light is absorbed by both pigments, there is very little blue in the mixture. The sum of this reflective mixture is a brownish olive tone.
Unlike colored light, pigments do not combine additively. Rather, their colors mix by the particles reflecting and absorbing light together. So while red light and green light combine to brown, actual red and green pigments blend in a similar muddy way.
Tertiary Colors
On the color wheel, tertiary colors are made by mixing a primary color with an adjacent secondary color. Adjacent colors share two primary colors between them. For example, red (primary) and orange (secondary) both contain red and yellow.
When a primary and secondary mix, the resulting tertiary contains attributes of both. Red-orange, for instance, is a vivid color midway between the two parents.
Green and brown are tertiary colors that contain aspects of both parent primaries. Green holds yellow and blue, while brown has red and yellow. Their muddy mixture retains these primaries in a desaturated way.
| Primary | Secondary | Tertiary |
|---|---|---|
| Red | Orange | Red-orange |
| Red | Brown | Brown tone |
| Yellow | Green | Yellow-green |
Color Psychology
Beyond the technical blending of red, green, and brown, there is also significance in these colors’ psychological associations. Red is commonly connected to passion, excitement, danger, or anger. Green often represents nature, renewal, harmony, and safety.
When combined optically, red and green’s intensity is diminished into a more neutral brown. This can symbolize nature reclaiming advances of humanity, like vines growing over an abandoned building. It can also represent the comedown after a vivid experience, the energy dissipating.
Context plays a key role in the meaning made from a red, green, brown color combination. It can convey natural cycles, fading intensity, complementary balance, or muddy confusion. The interpretation depends greatly on the colors’ use.
Examples from Art and Design
Many artists and designers have made use of the distinct red, green, and brown color relationship. Here are some notable examples:
Landscape Painting
Landscape painters often utilize the tertiary greens, browns, and earthy reds present in nature. These colors dominate many natural environments and are important for realistic depictions. Mixing greens with reds and browns helps capture the gradations of natural color.
Color Field Painting
Some color field painters like Mark Rothko layered blocks of complementary colors like red over green. The optical mixing creates new tones while also vibrating where the colors meet. This invites layered viewing, shifting with perspective.
Web Design
On the web, red and green are often used for contrasting call to actions. For example, a green purchase button next to red error messages. Browns bridge these commands neutrally without competing emphasis.
Packaging Design
Red and green carry cultural associations that are useful on packaging. Red conveys excitement, while green reads natural. Brown panels or text help adjust the balance, ensuring an energetic but down-to-earth impression.
Mixing Paints
Red and green paint can be mixed to intentionally make a tertiary brown for artistic purposes. Here is a step-by-step guide:
1. Select a red and green paint. Options include cadmium red and viridian green for opaque mixing. For translucent layering, try alizarin crimson and phthalo green.
2. Determine the ratio of each color. A 1:1 ratio makes an even brown. Adjusting the amounts shifts the balance towards red or green.
3. Thoroughly intermix the two paints on a palette. A palette knife can help blend the pigments smoothly.
4. The blended paint can be swatched to test the hue. Add more red or green as needed to adjust the tone.
5. Use the blended brown paint on the canvas as desired. Layering over other colors will subtly neutralize and mute them.
6. Clean brushes with water and soap between colors. Let brown paint mixture dry before sealing or varnishing the finished piece.
Why Red and Green Make Brown
While red and green are complementary colors, combining them results in a brownish tertiary shade. This is caused by the optical mixture of the colors in the eye, along with the physics of reflected light blending the pigments. Red and green lose their vivid intensity when merged.
The psychology of color also comes into play, with red’s energy and green’s vibrancy giving way to a more moderate brown. This color mixing concept applies equally to light, pigments, and perception. So whether blending colored spotlights or painting a landscape, red laid over green will make some form of brown.
Conclusion
Mixing complementary colors often produces duller, darker tones. But the interplay of red, green and brown has its own dynamic attributes. Optical vibrancy, symbolic connotations, and technical color relationships all factor into the red over green combination. Used thoughtfully, these colors can evoke natural harmony, shifting balance, and visual potency. While red and green remain opposites, artists mix them to generate intriguing new depths.
