Violet is a color between blue and red on the visible spectrum. It is one of the rainbow colors and sits at about 380-450 nm wavelength. Violet can be made by mixing red and blue light or pigments together in the right proportions. This article will explain the basics of how mixing colors of light and pigments works to create violet.
Additive vs Subtractive Color Mixing
There are two main ways to mix colors – additive and subtractive mixing.
Additive mixing involves combining light of different colors. When you mix red and blue light together, the eye perceives this as violet. This is because these two colors stimulate both the red and blue color receptors in your eyes at the same time. Red light has a wavelength of around 700 nm while blue is around 450 nm. Violet sits between these wavelengths.
Computer and TV screens use additive color mixing with red, blue and green light to create all the colors we see. So on a screen, combining intensities of red and blue light will make violet.
Subtractive mixing involves combining pigments. Pigments work by absorbing some wavelengths of light and reflecting others. For example, red pigment absorbs blue and green light while reflecting red.
When you mix paints, dyes or inks together, you are using subtractive mixing. Red and blue paint pigments each reflect their own color but absorb the other. When combined, the red absorbs the blue and the blue absorbs the red. What is left in the mix is the color that they both don’t absorb – violet.
So with pigments, mixing red and blue makes violet by the process of absorbing all but what is common between them.
Mixing Red and Blue Light
Red light and blue light can be mixed together using a computer screen, projectors or theater lighting to make violet. On a computer screen:
– Red light has a wavelength of around 700nm
– Blue light has a wavelength of around 450nm
– Violet light has a wavelength of about 400-450nm
So by displaying appropriate intensities of red and blue light, the eye will perceive this as violet since this stimulates both the red and blue color receptors.
For example, in HTML color codes, #FF0000 is full intensity red while #0000FF is full blue. Mixing different intensities of these can make violet:
– #BF40BF is a 75% red, 25% blue that appears violet
– #7F00FF is 50% red, 100% blue violet
– #8B008B is a 55% red, 55% blue violet
You can experiment by mixing RGB values like this using image editing software as well to produce violet colors.
The exact ratio of red to blue needed will depend on the hue of violet you want. More blue will give a cooler, purplish violet while more red will be a warmer, pinkish hue. But any combination of intensities of red and blue light will stimulate both color receptors to give a violet visible color.
Mixing Red and Blue Pigments
You can mix red and blue pigmented paints, dyes or inks to make a violet color through subtractive mixing.
Some examples using common pigment types:
| Red Pigment | Blue Pigment |
| Cadmium red | Ultramarine blue |
| Alizarin crimson | Prussian blue |
| Quinacridone red | Phthalo blue |
The mixing process involves:
– Taking a red pigment that reflects red but absorbs blue/green light
– Taking a blue pigment that reflects blue but absorbs red/yellow light
– Combining these paints so the common wavelength left is violet
For example, cadmium red reflects red light but absorbs blue and green light. Ultramarine blue reflects blue but absorbs red and yellow. When mixed, the red absorbs the blue and blue absorbs the red. So the only wavelength left in the mix is violet, giving this violet color.
The exact hue of violet can be controlled by adjusting the ratio of the red and blue pigments. More blue pigment will give a cooler, purple-leaning violet while more red will appear pinkish. But any combination will produce a violet paint color through the physics of subtractive color mixing.
Other Ways to Make Violet
While mixing red and blue is the standard way to make violet, there are some other options as well:
– Mixing Magenta and Blue – Magenta sits between red and violet wavelengths so combining with blue also makes violet.
– Mixing Ultramarine Violet Pigments – Some specific pigments are made by chemists to directly reflect violet wavelengths. These ready-made violet pigments can be used instead of mixing.
– Cooling Down Reds – Increasing blue tones in a red will shift it towards violet. So adding a touch of blue to warm reds is another way to create violet shades.
– Warming Up Blues – Likewise, adding a bit of red/yellow to blues shifts them violet. So subtle warming of cooler blues indirectly mixes a violet.
So while combining red and blue is the classic and most reliable way, you can take some shortcuts by using pre-made pigments or by subtly adjusting existing reds and blues. The key is ensuring there is a balance of both red and blue wavelengths present.
Conclusion
Violet is made by combining red and blue wavelengths of light. Additive mixing of red and blue light creates violet through combining the light spectra. Subtractive pigment mixing produces violet by each pigment absorbing the other’s wavelength.
While computers mix light, paints mix pigments subtractively. But both rely on blending red and blue to make the eye see violet. Small adjustments to the red-blue balance control the exact purple hue. Understanding these color mixing principles allows you to reliably mix a violet for any application.
