The color orange is a mixture of red and yellow. In the RGB (red, green, blue) color model, orange is made by combining red and green light. The specific ratio of red and green light needed to make orange depends on the desired shade of orange. By adjusting the amount of red and green, various shades of orange can be produced.
How the RGB Color Model Works
The RGB color model is based on the way human vision perceives color. The retina of the human eye contains photoreceptor cells called cones. There are three types of cones, each responsive to different wavelengths of light:
- Red cones – sensitive to long wavelengths
- Green cones – sensitive to medium wavelengths
- Blue cones – sensitive to short wavelengths
When red, green, and blue light enters the eye in various combinations and intensities, the cones are stimulated to different degrees. The brain interprets these signals as different colors.
In the RGB model, colors are produced by mixing red, green and blue light. By adjusting the intensity of each component, a wide range of colors can be created. For example:
- Red light stimulates the red cones
- Green light stimulates the green cones
- Blue light stimulates the blue cones
- A mix of red and green stimulates the red and green cones to create yellow
- A mix of all three stimulates the cones to create white
RGB values are generally specified on a scale from 0 to 255, where 0 means none of that color and 255 is the maximum intensity. By mixing different RGB values, millions of colors can be represented.
Primary Colors of Light vs. Paint
It’s important to note that the primary colors of light (red, green, blue) are different from the primary colors of paint and other pigments (red, yellow, blue).
With paints and pigments, the primary colors are those that can be mixed to create other colors but cannot be created by mixing other colors. Red, yellow and blue fit this definition for pigments.
Light works differently. Red, green and blue are chosen as the primary colors for light because they closely match the peak sensitivities of the three types of cones cells in the human eye. Mixing red, green and blue light stimulates our cones cells to allow us to perceive a wide range of colors.
So for creating colors with light, as in TVs and computer monitors, red, green and blue are the primary colors. For mixing paints and other pigments, the primary colors are red, yellow and blue.
Creating Orange with RGB
Orange is a secondary color, meaning it can be created by mixing two primary colors. Specifically, orange is a mix of red and yellow.
In the RGB model, there is no wavelength of light that corresponds directly to yellow. But yellow can be simulated by mixing red and green light.
So to make orange with RGB:
- Start with a high value for red (around 200-255)
- Add a medium value for green (around 100-150)
- Use a low value for blue (around 0-50)
For example, an RGB value of R=255, G=165, B=0 produces a bright orange color:
| Red | 255 |
| Green | 165 |
| Blue | 0 |
The high red value stimulates the red cones strongly. The medium green value stimulates the green cones to a lesser degree. The low blue leaves the blue cones largely unaffected. The brain interprets this combination of cone stimulations as orange.
Adjusting the exact balance of red and green allows for different shades of orange to be produced.
Shades of Orange RGB Values
Here are some example RGB values for common shades of orange:
| Shade | Red | Green | Blue |
| Dark orange | 200 | 100 | 0 |
| Orange | 255 | 165 | 0 |
| Light orange | 255 | 200 | 0 |
| Red-orange | 255 | 69 | 0 |
| Yellow-orange | 255 | 193 | 37 |
As you can see, darker oranges have a lower green value while lighter oranges have a higher green value. More redness is created by boosting the red and reducing the green. More yellowness comes from increasing the green.
Conclusion
In summary, orange is made in the RGB color model by combining high amounts of red with medium amounts of green. This stimulates the red and green cones in the eye, which the brain perceives as orange. Different shades can be created by adjusting the exact balance between the red and green values. While red, yellow and blue are the primary colors of pigments, red, green and blue are the primary colors of light and are used in RGB color models. So mixing red and green light is the way to produce orange on screens and displays.