The primary colors are the building blocks of all color. But there is debate over whether the primary colors are red, yellow, and blue (RYB) or red, green, and blue (RGB). This article will examine the history and science behind both color systems to help understand when and why each is used.
A Brief History of RYB and RGB
The RYB (red, yellow, blue) color model dates back centuries and originated with painters mixing paint pigments. The RGB (red, green, blue) model emerged more recently with color television and digital displays which emit rather than reflect light.
RYB and Traditional Painting
The RYB color model was first theorized by Isaac Newton in the 17th century when he showed that all colors could be created by mixing red, yellow, and blue paint pigments. This became the standard for painters and remained so until the 19th century with the emergence of modern color theory.
The RYB system works for paint mixing because the pigments subtract wavelengths of light. Yellow pigment absorbs blue light, magenta (made from mixing red and blue) absorbs green, and cyan (made from blue and green) absorbs red. Combining all three primary pigments theoretically absorbs all visible light, creating black.
RGB and Additive Color
In the 19th century, James Clerk Maxwell showed that color perception relies on three types of cone cells in our eyes, each sensitive to red, green or blue wavelengths of light. This discovery shifted color theory from pigment mixing (RYB and subtractive color) to colored light addition (RGB and additive color).
Additive RGB color starts with darkness. Light sources like computer screens or TVs emit the primary colors of light – red, green and blue – which combine additively to create other colors. Mixing all three primaries of light creates white. Early color photographs and color films also used RGB systems.
The Science Behind RYB and RGB
While traditional RYB make intuitive sense from mixing paints, the RGB model is more scientifically accurate for light and color perception. Here’s a closer look at the color science.
RGB Aligns with Cone Cells
As Maxwell discovered, we have three types of cone cells for absorbing red, green and blue light. This forms the physiological basis of human color vision and color theory. The RGB colors align directly with these cone cells and additive light physics.
RYB Has Visual Weaknesses
The RYB system is less accurate for representing how colors are perceived. For example, magenta (red + blue) has no yellow pigment. Yet on color wheels, magenta is opposite green and contains no yellow. This demonstrates limitations in perceptual accuracy.
RGB Can Produce a Wider Color Gamut
The range of colors that can be produced is called the color gamut. RGB has a wider gamut because it mixes light directly aligned with human vision (the cone cells). RYB is limited by the narrower range of pigments. There are some colors producible in RGB that are outside gamut in RYB.
When to Use RYB vs RGB
Despite the strengths of RGB, RYB remains in use particularly by artists and painters. Here are guidelines for when each color system is most applicable:
Use RYB for Painting
RYB is best suited for working with physical paints. The primary pigments are easily mixed to create a wide range of hues acceptable for artistry. RYB also fits with long artistic traditions and color theory learned by painters over centuries.
Use RGB for Digital Media
RGB is designed for emitting light which matches digital screens and displays. Televisions, phones, computers, and other devices all use RGB systems to transmit color information as combinations of red, green and blue light. RGB also aligns with digital image formats and programming.
Either May Work for Basic Color Education
When teaching children the basics about color mixing, either RYB or RGB can work as simplified models. Additive vs. subtractive color may be too advanced a concept at early ages. Introducing the primaries of either system can provide the foundation for more detailed color theory later.
| Color System | Primary Colors | Color Mixing Process | Best Uses |
|---|---|---|---|
| RYB | Red, Yellow, Blue | Subtractive (pigment) | Painting, traditional arts |
| RGB | Red, Green, Blue | Additive (light) | Digital screens, TVs, computers |
Conclusion
While RYB has tradition on its side, RGB is a more accurate model based on human vision and physics of light. But each system remains useful in different contexts. Understanding the history and science behind both color models provides deeper appreciation for the complexity of color perception and representation. Whichever primaries are used, color theory remains a fascinating intersection of art, science and the human experience.