This is an interesting question that has intrigued artists, scientists, and anyone curious about color theory for centuries. When all colors of light are combined, the result is white light. However, when it comes to pigments and dyes, mixing all colors results in black. In this article, we’ll explore the science behind mixing colors, look at some examples, and explain why you get white with light and black with pigments.
How Light and Pigments Work
To understand what happens when colors are mixed, we first need to understand the difference between light and pigments.
Light is composed of wavelengths across the visible spectrum. The wavelengths we see as red, green, and blue can be combined to create all the colors we perceive. Televisions and computer monitors create color by mixing red, green and blue light. When all wavelengths of visible light are present, we see white.
Pigments and dyes work differently than light. They absorb certain wavelengths and reflect others back to our eyes. For example, a red pigment absorbs all wavelengths except red, which it reflects to our eyes. When two pigments are mixed, both pigments absorb more wavelengths, reflecting back less overall light. The more pigments that are mixed, the more wavelengths are absorbed and the darker the color becomes. Eventually, a blend of all pigments appears black because all wavelengths are absorbed.
Mixing Colored Light
When beams of pure red, green, and blue light are shined together onto a white surface, the light combines to produce white. This is known as an additive color model. Red, green and blue are called primary colors of light.
Computer and TV screens provide an excellent example of additive color mixing. Pixels on a screen contain tiny red, green and blue LEDs. When the LEDs are turned on at different brightnesses, our eyes integrate the lights to see all the colors of the spectrum. With all LEDs shining equally bright, the pixel appears white.
Mixing Paints and Dyes
Mixing pigments like paint, ink, dye or colorants results in a subtractive color model. As more pigments are added together, more wavelengths of light get absorbed, producing a darker color.
The primary colors for pigment mixing are cyan, magenta and yellow. These three colors absorb complements of the primary colors of light. For example, cyan paint absorbs red light, reflecting just green and blue back to our eyes.
When cyan, magenta and yellow pigments are mixed together, almost all wavelengths are absorbed. There is so little light reflected back that we perceive the mix as black.
Examples of Mixing Paints
Mixing complementary paint colors vividly illustrates how combining more pigments results in black:
| Red + Green | Dark Brown |
| Orange + Blue | Dark Brown |
| Yellow + Violet | Dark Grey |
Combining all primary paint pigments also produces black:
| Cyan + Magenta + Yellow | Black |
This table shows step-by-step how mixing equal parts of more and more paint colors results in progressively darker browns, eventually reaching black:
| Red + Yellow | Orange |
| Red + Yellow + Blue | Dark orange brown |
| Red + Yellow + Blue + Green | Darker brown |
| Red + Yellow + Blue + Green + Purple | Very dark brown |
| Red + Yellow + Blue + Green + Purple + Cyan + Magenta | Black |
These examples clearly demonstrate how combining more pigments absorbs more light wavelengths, progressively darkening the mix until eventually reaching black.
Mixing Colored Light vs. Pigments
The key difference between mixing light and mixing pigments is:
– Light combines additively to produce white
– Pigments combine subtractively to produce black
This can be summarized:
| Mixing Light Colors | Additive – Combines to white |
| Mixing Pigment Colors | Subtractive – Combines to black |
The additive mixing of light is based on combining wavelengths, while subtractive mixing of pigments is based on absorbing wavelengths.
Real World Examples
We can observe the subtractive color model at work through some real world examples of mixing pigments:
– Mixing all paint colors together produces black
– Combining all printing inks produces black
– Melting many crayon colors together yields a black wax crayon
Coffee provides an everyday example. Adding cream, which contains fat molecules that scatter light, makes coffee appear lighter. The more cream you add, the lighter the coffee becomes.
Plants also demonstrate subtractive color mixing. The green chlorophyll in leaves absorbs red and blue light while reflecting green. In autumn, decreasing chlorophyll unmasks yellow and orange pigments that were present all along in the leaves.
Conclusion
When it comes to mixing colors, light and pigments behave very differently. Combining beams of colored light additively produces white. But mixing pigments like paint, ink, or dye subtractively results in black as more wavelengths are absorbed. This is because light mixes by adding wavelengths, while pigments mix by absorbing wavelengths. So in summary, mixing all colors of light makes white, while mixing all colors of pigment makes black. Understanding the science behind color mixing provides deeper insight into everything from displays to paintings.
