When it comes to mixing colors, blue and yellow are considered primary colors. This means they cannot be created by mixing other colors together. When combined, blue and yellow make a secondary color called green.
The Basics of Mixing Blue and Yellow
Blue and yellow are located opposite each other on the color wheel. Colors located opposite each other are called complementary colors. When mixed together, they create a vibrant secondary color.
Both blue and yellow have strong pigments. This means just a small amount of blue or yellow paint mixed together will result in a bold green color. The more saturated the original blue and yellow colors are, the more saturated the resulting green will be.
Light blue and light yellow will make a softer, pastel green. Conversely, mixing a deep navy blue with a bright lemon yellow will create a jewel-toned green. The shade of the blue and yellow determines the shade of the green.
The Science Behind Mixing Blue and Yellow
On a technical level, mixing blue and yellow produces green because of the way light interacts with our eyes. The rods and cones in our eyes detect different wavelengths of light. Blue light has a shorter wavelength while yellow light has a longer wavelength.
When blue and yellow light enter our eyes simultaneously, the rods and cones combine the inputs and our brain perceives the intermediate wavelength as green. So green is actually just our visual interpretation of the blending of blue and yellow wavelengths of light.
The same principles apply to mixing blue and yellow pigments. The pigments selectively absorb and reflect different wavelengths. Where the reflected wavelengths overlap we see green.
Examples of Mixing Blue and Yellow
Here are some common examples of blue and yellow mixing to make green:
- Cyan blue and lemon yellow make a bright lime green
- Royal blue and golden yellow make a rich forest green
- Light blue and pale yellow make a seafoam green
- Navy blue and bright yellow make a kelly green
- Turquoise blue and mustard yellow make a chartreuse green
The mixing possibilities are endless. By adjusting the blue and yellow hues and their proportions, artists can mix a wide range of green shades and intensities.
Uses for Green Made from Blue and Yellow
Artists mix blue and yellow to produce green for many purposes, including:
- Painting landscapes – greens are ubiquitous in nature
- Coloring frogs, turtles, lizards and other green creatures
- Making green clothing, furnishings, toys, etc.
- Producing food coloring for green-colored foods
- Tinting cosmetics like eye shadows and nail polishes
- Coloring novelty items like green beer on St. Patrick’s Day
Green is associated with nature, growth, renewal and environment causes. It’s a versatile color artists create by blending blue and yellow.
Other Ways to Make Green
While combining blue and yellow is the primary way to make green, it’s not the only way. Other color mixing options to produce green include:
- Cyan and magenta (printing process colors)
- Blue and red
- Yellow and cyan
- Yellow and black
- Yellow, blue and red mixed together
You can also desaturate pure green by adding white, gray or black to make mint, sage, olive and other dull greens.
The Color Wheel
The relationship between blue, yellow and green is best visualized on the color wheel. The color wheel demonstrates how colors relate based on their pigment composition and wavelength of light.
| Primary Colors | Secondary Colors | Tertiary Colors |
|---|---|---|
| Yellow | Green | Yellow-green |
| Blue | Purple | Blue-purple |
| Red | Orange | Red-orange |
As shown on the color wheel, yellow and blue are primary colors located opposite each other. Mixing these primaries makes the secondary color green. Green sits between yellow and blue on the wheel.
You can also see the intermediate, tertiary colors that contain a mixture of the neighboring primary and secondary colors. For example, yellow-green sits between green and yellow.
How the Eye Perceives Color
Our eyes contain special photoreceptor cells called rods and cones. Rods detect brightness and shadows. Cones detect color and come in three types:
- S cones respond to short wavelengths of light and detect blue colors.
- M cones respond to medium wavelengths and detect green.
- L cones respond to long wavelengths and detect red.
These cone cells are very sensitive to their particular wavelengths. But they also pick up some of the neighboring wavelengths, overlapping with each other. This means our brain receives both the dominant and supporting color data for each cone.
When blue and yellow light enters the eye, the S cones detect blue while the M and L cones pick up the yellow wavelengths to varying degrees. Where the S cone and M cone sensitivities overlap, our brain perceives the color green.
Cone Response to Blue and Yellow Light
| Cone Type | Main Color Detected | Response to Blue Light | Response to Yellow Light |
|---|---|---|---|
| S (short wavelength) | Blue | Strong | Very weak |
| M (medium wavelength) | Green | Moderate | Strong |
| L (long wavelength) | Red | Weak | Moderate |
As shown in the table, the S cones strongly detect blue but weakly detect yellow. The M cones strongly detect yellow but moderately detect blue. When stimulated together by both wavelengths, the brain merges the overlapping signals into the perception of green.
Cone Response Curves
The sensitivity of the three cone types across the visible color spectrum is demonstrated in the following graph of cone response curves:
| Wavelength (nm) | S cone response | M cone response | L cone response |
|---|---|---|---|
| 400-450 (violets) | Strong | Very weak | None |
| 450-495 (blues) | Very strong | Weak | None |
| 495-570 (greens) | Moderate | Strong | Weak |
| 570-590 (yellows) | Weak | Very strong | Moderate |
| 590-650 (reds) | Very weak | Moderate | Strong |
You can see the S cone response peaks in the short blue wavelengths while the M cone response peaks in the medium green-yellow wavelengths. The brain combines the overlapping moderate S cone response and strong M cone response in the 500-570 nm range to perceive green.
Pigment Absorption and Reflection
Mixing blue and yellow pigments produces green through similar principles of light absorption and reflection. Pigments contain color molecules that selectively absorb certain wavelengths while reflecting others.
When green is created by mixing paints, inks, dyes or other colored media, here is what happens:
- The yellow pigments absorb blues and violets and reflect green and red.
- The blue pigments absorb oranges and reds and reflect blues and greens.
- Where the reflected wavelengths of the blue and yellow pigments overlap, we see green.
So mixing blue and yellow pigments creates the full spectrum of green colors based on the shared reflected wavelengths between the blue and yellow pigment molecules.
Subtractive vs. Additive Color Mixing
There are two main types of color mixing:
- Subtractive – Combining pigments/dyes/paints/inks (Cyan, Magenta, Yellow)
- Additive – Combining emitted light (Red, Green, Blue)
Mixing blue and yellow pigments is subtractive color mixing. The pigments selectively absorb and subtract wavelengths from white light.
Mixing blue and yellow light is additive color mixing. The combined wavelengths add up to create new light colors for monitors and displays.
While light and pigment color mixing follow different technical processes, they both combine blue and yellow to create the color green through overlapping wavelengths and absorption/reflection.
Mixing Paints vs. Light
| Method | Primary Colors | Secondary Colors | How it Works |
|---|---|---|---|
| Mixing Paints | Cyan, Magenta, Yellow | Red, Blue, Green | Pigments absorb/reflect specific wavelengths |
| Mixing Light | Red, Green, Blue | Cyan, Magenta, Yellow | Light wavelengths add together |
As shown, paints use the subtractive CMY primaries while light uses the additive RGB primaries. But both mix blue and yellow to make green through absorption/reflection and wavelength addition.
Conclusion
In summary, combining blue and yellow makes green through the merging of their light wavelengths or pigment reflections. On the color wheel, blue and yellow are primary colors located directly opposite each other. When mixed, they form the vibrant secondary color green.
The shade of green depends on the specific hues and proportions of blue and yellow used. Understanding color theory helps artists intelligently mix custom greens by blending blue and yellow.
