Purple and violet are often used interchangeably to refer to shades ranging from light reddish-purple to dark bluish-purple. However, some sources consider them to be technically different colors based on their specific wavelengths of light.
The Difference Between Purple and Violet
In the traditional color wheel used by artists and designers, purple sits between red and blue. Violet is considered a distinct hue that falls between purple and blue.
On the light spectrum, violet light has a shorter wavelength than purple light. Violet light ranges from 380-450 nanometers, while purple light is around 455-485 nanometers.
This means violet has a higher frequency and more energy than purple. The human eye perceives shorter wavelengths as more blue and longer wavelengths as more red. So violet appears bluer and more intense than purple.
How the Eye Perceives Color
The human eye contains cone cells that are sensitive to different wavelengths of light. There are three types of cone cells:
- S-cones: sensitive to short blue wavelengths
- M-cones: sensitive to medium green wavelengths
- L-cones: sensitive to long red wavelengths
When light hits the eye, the cone cells send signals to the brain about the intensity of blue, green, and red. The brain combines these signals to produce the perception of different colors.
Violet stimulates the S-cones more than the M and L cones. Purple stimulates both the S and L cones fairly equally. So violet appears more blue and purple appears more reddish.
The Visible Spectrum
The visible light spectrum ranges from about 380-750 nanometers. Within this spectrum, violet and purple fall in the shorter wavelength range from around 380-500 nm:
| Color | Wavelength Range (nm) |
|---|---|
| Violet | 380-450 |
| Purple | 450-485 |
| Blue | 485-500 |
As the wavelength increases, the light shifts from violet to purple to blue. But there is some overlap between violet and purple wavelengths.
The CIE Chromaticity Diagram
The International Commission on Illumination (CIE) developed a chromaticity diagram that maps out the full range of human visible colors. This diagram displays pure spectral wavelengths around the edge and mixed colors toward the center.
On the CIE diagram, violet and purple lie close together but in slightly different locations. Violet leans more toward blue and purple leans between red and blue.
The CIE chromaticity diagram showing the positions of violet and purple.
How Humans Perceive Violet vs. Purple
Although violet and purple represent different spectral wavelengths, the human eye cannot easily distinguish them. Here are some factors that affect color perception:
- Metamerism – Different combinations of wavelengths can produce the same perceived color.
- Color blindness – About 1 in 12 men cannot distinguish red and green due to cone cell deficiencies.
- Age – The lens yellows over time, reducing perception of violet and blue hues.
- Ambient light – Surrounding colors influence the appearance of a specific hue.
Due to these perceptual limitations, most people see violet and purple as very similar shades. However, some individuals with exceptional color vision can detect a subtle difference.
Usage of Violet vs. Purple
In art, fashion, interior design, and other fields, violet and purple are generally used interchangeably. But some sources distinguish them in the following ways:
- Violet has a cooler, bluer tone compared to purple.
- Light purple is considered a less saturated, pale tone of purple.
- Violet is associated with spirituality, mysticism, and magic.
- Purple is associated with royalty, luxury, and ambition.
Here are some examples of how violet and purple are described differently:
| Violet | Purple |
|---|---|
| Violet eyes | Purple eyeshadow |
| Violet flowers | Purple plums |
| Violet aura | Purple robes (royalty) |
Conclusion
While violet and purple have distinct wavelengths on the light spectrum, most people perceive them as very similar. Violet leans slightly bluer than purple. But the two colors occupy a continuous range of hues from red to blue.
The distinction between violet and purple is subtle and often subjective. Usage varies based on context, artistic interpretation, and individual color perception. But both violet and purple convey richness, imagination, and beauty through their deep hues.