Blue and yellow are two primary colors. When mixed together in the right proportions, they will make the secondary color green. In this article, we will examine the color theory behind mixing blue and yellow to create green.
The Basics of Color Mixing
In color theory, there are 3 primary colors – red, blue and yellow. These are colors that cannot be created by mixing other colors together. All other colors are derived from some combination of the primary colors.
When you mix two primary colors together, you get a secondary color. The secondary colors are purple, orange and green. For example:
- Red + Blue = Purple
- Red + Yellow = Orange
- Blue + Yellow = Green
Tertiary colors are created by mixing a primary color with a secondary color next to it on the color wheel. For instance:
- Red + Purple = Red-purple
- Blue + Green = Blue-green
- Yellow + Orange = Yellow-orange
The basic color wheel showing the primary, secondary and tertiary colors looks like this:
| Primary | Secondary | Primary |
| Red | Purple | Blue |
| Red-purple | Blue-purple | Blue-green |
| Red | Orange | Yellow |
| Red-orange | Yellow-orange | Yellow-green |
| Red | Yellow |
So when it comes to mixing blue and yellow, as two primary colors on the wheel, the resulting secondary color will be green.
The Pigments in Blue and Yellow Paint
When working with paints, the two common pigments used to create blue and yellow are:
- Blue – Ultramarine or Prussian blue
- Yellow – Cadmium yellow or Hansa yellow
Ultramarine blue is a deep blue pigment made from the semi-precious lapis lazuli stone. Prussian blue is a synthetic pigment discovered in the early 1700s. It has a dark blue hue with greenish undertones.
Cadmium yellow is a bright, lemony yellow made from cadmium sulfide. Hansa yellow is a synthetic organic pigment known for its brightness and opacity.
When these blue and yellow pigments are mixed together, they will start to neutralize each other and eventually blend into green. The exact shade of green will depend on the ratio of blue to yellow pigments.
Mixing Paint to Make Green
If you want to mix green yourself from blue and yellow paint, here are some tips:
- Use a palette or flat surface for mixing the colors.
- Start with applying small amounts of blue and yellow paint side by side.
- Use a paintbrush or palette knife to blend the edges where they meet.
- Gradually mix the two colors together, controlling the proportions.
- Add more blue or yellow as needed to adjust the green shade.
- Test your mixed green color on a scrap paper before applying it.
Some examples of green shades you can mix are:
- More blue for a cooler, teal green
- More yellow for a warmer, lime green
- Equal parts for a bright spring green
When blending blue and yellow, start with a small amount of paint and add gradually. It’s easier to intensify a color than to dilute it after mixing too much. Work in thin layers and allow time to dry between mixing to prevent colors from getting muddy.
Complementary Colors
Blue and yellow are considered complementary colors on the color wheel. This means they are directly opposite each other. Complementary color pairs contrast strongly with each other.
When complementary colors are mixed together, they neutralize each other. This causes the resulting mix to be more muted, shaded or brown. Mixing complements is how secondary and tertiary colors are created.
Some examples of complementary color pairs are:
- Blue & yellow
- Red & green
- Purple & yellow-orange
Using complementary colors together makes them appear more intense. This is why the blue sky seems bluer against yellow sunrays. Complementary colors are visually striking and often used together in graphic design.
The Physics of Light and Color
On a technical level, mixing blue and yellow light produces green due to how our eyes perceive different wavelengths of light.
Blue light has a wavelength of about 470 nanometers (nm). Yellow light is around 570 nm. When these wavelengths are mixed, the result is perceived as green light at around 510 nm wavelength.
This is described by the trichromatic theory of color vision. Our eyes have three types of cone photoreceptor cells that respond to short (blue), middle (green) and long (yellow/red) light wavelengths.
When the blue and yellow cone cells are stimulated simultaneously by a mix of blue and yellow light, the brain interprets the signals as the color green.
Reflective vs Transmissive Color Mixing
We’ve looked at mixing blue and yellow pigments to make green paint. But there are actually two types of color mixing:
- Reflective (Subtractive) – Mixing pigments, dyes, paints. Uses CMYK model.
- Transmissive (Additive) – Mixing light sources. Uses RGB model.
Reflective mixing is when colored materials such as inks, pigments or dyes are blended together. The mixed colors subtract wavelengths, producing a darker result.
Transmissive mixing involves blending light sources like beams of colored light. The combined wavelengths add up, making the result lighter.
Computer and TV screens use transmissive RGB (red, green, blue) color mixing to create the colors we see. Printing uses reflective CMYK (cyan, magenta, yellow, black) inks to absorb and reflect different color wavelengths.
Cultural Associations of Blue, Yellow and Green
In addition to their scientific properties, colors also have cultural symbolism and associations attached to them. Here are some examples for blue, yellow and green:
- Blue – calm, soothing, professional, masculine, cold, depressing, cleanliness
- Yellow – bright, cheerful, playful, optimistic, warning, cowardice
- Green – natural, peaceful, growth, environmental, money, renewal
Blue and green especially have very positive environmental associations. Blue evokes the sea and sky, while green represents nature, trees, grass and vegetation.
Green is also tied to renewal and growth, both literally in nature and metaphorically for ideas like “the green movement”. It strikes balance as a secondary color between warm yellow and cool blue.
Examples of Blue and Yellow Creating Green
Here are some examples of mixing blue and yellow to create green:
- Cyan and yellow printer inks produce green colors.
- Traffic lights combine blue, yellow and green lights.
- TV/computer screens mix blue and green RGB pixels to display green.
- The human eye sees green when blue and yellow wavelengths enter it.
- Green results from blending blue and yellow on a painter’s palette.
- The flag of Brazil has a blue circle and yellow diamond that mix to look green.
- Green flowers like orchids and hydrangeas have blue and yellow pigments.
Wherever blue and yellow come together, whether light, paints or dyes, the resulting blend we see is some shade of green. The principles of color theory explain how our eyes and brains perceive this mix as green.
Conclusion
In summary, mixing the primary colors blue and yellow does create the secondary color green. This applies to both additive light mixing and subtractive pigment mixing. The specific green hue produced depends on the proportion of blue to yellow. Color theory and physics of light help explain why we perceive a blue-yellow mix as green.
Blue and yellow are complementary colors which strongly contrast. Mixing complements neutralizes their intensities, creating more natural hues. Green results when blending blue calmness with yellow’s energy and warmth. This makes green a balanced, harmonious color evoking nature and renewal.
