Subtractive primary colors are a set of pigments that can be combined to produce a wide range of colors through subtractive color mixing. Unlike additive primaries that create color by emitting light, subtractive primaries work by absorbing certain wavelengths of light and reflecting others. This absorption and reflection of light is what gives rise to the vivid colors we see in paints, dyes, inks, and other pigments.
Definition of subtractive primaries
The subtractive primary colors are cyan, magenta, and yellow. These three colors together can be mixed to produce a wide gamut of colors by selectively absorbing parts of the visible light spectrum. Cyan absorbs red light, magenta absorbs green light, and yellow absorbs blue light. When two subtractive primaries are combined, the resulting secondary color reflects only the wavelength not absorbed by either pigment. For example, red light is reflected by magenta (which absorbs green), and green light is reflected by yellow (which absorbs blue). This means mixing magenta and yellow together absorbs both blue and green light, reflecting only red light back to our eyes and producing red.
How subtractive color mixing works
Subtractive color mixing relies on the absorption and reflection of light rather than the emission of light in additive color mixing. Objects appear a certain color because they absorb some wavelengths of visible light and reflect others. For example, a red object absorbs all wavelengths except red, reflecting only red light to our eyes. Pigments selectively absorb parts of the light spectrum, allowing the wavelengths they don’t absorb to be reflected back. Combining pigments expands the range of wavelengths that can be absorbed.
When subtractive primaries cyan, magenta, and yellow are combined:
- Cyan absorbs red light
- Magenta absorbs green light
- Yellow absorbs blue light
Mixing two primaries creates a secondary color that reflects the only wavelength not absorbed by either pigment. For example:
- Cyan + Magenta = Blue (absorbs red + green, reflects blue)
- Cyan + Yellow = Green (absorbs red + blue, reflects green)
- Magenta + Yellow = Red (absorbs green + blue, reflects red)
When all three primaries cyan, magenta, and yellow are combined, they absorb most visible light, creating black. The more pigments that are combined, the more wavelengths are absorbed, eventually creating black when all light is absorbed.
Advantages of subtractive color
There are several key advantages to subtractive color mixing with pigments:
- Wider color gamut – By selectively absorbing parts of the spectrum, subtractive primaries can produce a wide range of colors, including vibrant bright colors not possible with additive mixing alone.
- Darker colors – Subtractive mixing allows the creation of true dark blacks by combining pigments to absorb most light wavelengths.
- Reflectance – Pigment colors result from reflected light, making them visible on opaque surfaces compared to emitted light in additive color.
- Practical applications – Subtractive color has many practical uses in paints, dyes, inks, and other pigmented materials all around us.
Comparison to additive primaries
Additive and subtractive color mixing use different primary colors and principles to create various hues. This table compares some key differences:
| Additive Primaries | Subtractive Primaries |
|---|---|
| Red, green, blue light | Cyan, magenta, yellow pigments |
| Emit light | Absorb and reflect light |
| Additive mixing | Subtractive mixing |
| Produces lighter colors | Produces darker colors |
| Used for TV, computer screens | Used for paints, inks, dyes |
While both methods create color through different light interactions, subtractive and additive color mixing complement each other. Displays use additive RGB primaries to emit color, while printers overlay cyan, magenta, yellow, and black pigments to absorb light and reflect color to physical surfaces.
Subtractive primaries in printing
Subtractive primaries are essential for full-color printing. Cyan, magenta, and yellow inks can be overlaid in varying amounts to generate a wide range of hues and colors during printing. Black ink is also added to create darker colors and adjust luminance.
In four-color process printing, cyan, magenta, yellow, and black (CMYK) inks are printed in tiny dots that overlap to create various colors through subtractive mixing. By controlling the proportion of each ink, printers can recreate color images accurately.
The CMYK color model used in printing relies on the cyan, magenta, and yellow subtractive primaries to recreate colors through absorption and reflection of light from the printed inks.
Subtractive primaries in other applications
Beyond printing, subtractive primaries have many practical applications:
- Painting – Paints mix pigments using subtractive color principles to create various hues.
- Dyes – Fabrics are colored with dye pigments that absorb and reflect select wavelengths.
- Inks – Pens and markers mix cyan, magenta, and yellow inks to generate colors.
- Photography – Color film uses layers of cyan, magenta, and yellow dyes to create color images.
- Makeup – Cosmetics like eye shadow mix various pigments to absorb and reflect light.
Wherever color is needed for physical objects, surfaces, or materials, subtractive color mixing allows colors to be reproduced in our physical world.
Subtractive vs additive color in design
In design applications, both additive and subtractive color principles must be considered together. Designs are often created using RGB additive primaries for digital screens. But the final designs must also translate accurately to CMYK subtractive primaries for print production.
Converting between color spaces can be challenging, as some colors in RGB are outside the printable gamut in CMYK. Designers must check designs in both additive RGB and subtractive CMYK to ensure colors translate properly between mediums.
Conclusion
Understanding subtractive color is essential for working with pigments and producing color for physical materials. Combining cyan, magenta, and yellow pigments allows a wide spectrum of hues to be created through selective absorption and reflection of light.
Subtractive primaries produce color differently than additive primaries like RGB, but both play important complementary roles. Whether designing for digital screens or printed materials, having a solid grasp of subtractive and additive color mixing helps create accurate, vibrant colors in any medium.
