Purple is a color that has long captivated human imagination. Throughout history, it has been associated with royalty, spirituality, and magic. But where does this enchanting color come from? How is the color purple made and used in art, fashion, and everyday life?
The Science of Purple
On the color wheel, purple sits between red and blue. In terms of wavelengths of light, it’s a combination of the longest wavelengths of red (around 700 nm) and the shortest wavelengths of blue (around 400 nm). When these wavelengths mix in the eye, our brains interpret it as the color purple.
Purple has the shortest wavelength of all the colors in the visible spectrum. It occupies the end portion of the spectrum of light that is visible to the human eye, just before ultraviolet rays.
How the Eye Perceives Purple
Inside the retina of the human eye are special receptor cells called cones. There are three types of cones, each responsible for detecting different colors:
- S cones detect short blue wavelengths of light
- M cones detect medium green wavelengths
- L cones detect long red wavelengths
When both the L and S cones are stimulated equally, the brain combines the signals and perceives the color purple. The molecules responsible for purple vision are rhodopsin in red cones and cyanopsin in blue cones.
Natural Pigments that Produce Purple
Throughout history, humans have found creative ways to extract purple pigments from nature. Here are some of the natural compounds that have been used:
- Murex sea snails – The Phoenicians gathered these sea creatures from the Mediterranean to produce Tyrian purple, a highly prized dye.
- Lichens – Rock tripe and other lichen species create purple pigments.
- Purpura pansa – This sea snail collected off the coast of South America secretes purple fluid.
- Fruits and berries – Blackcurrants, elderberries, blackberries, and other deep purple foods have been used as dyes.
- Purple carrots – Originally from Afghanistan, these vibrant purple carrots get their pigment from anthocyanins.
When exposed to sunlight and oxygen, many natural purple pigments tend to fade quickly. As a result, developing long-lasting purple dyes has been a challenge throughout history.
Early Synthetic Purple Dyes
In 1856, an 18-year-old English chemist named William Henry Perkin accidentally created the first synthetic purple dye while trying to synthesize the malaria drug quinine. This dye, known as mauve or Perkin’s mauve, allowed the mass production of affordable purple fabrics.
Other early synthetic dyes soon followed, including:
- Dahlia mauve – A reddish-purple dye developed in Germany in 1884.
- Cresyl fast violet B – A bluish-purple dye manufactured starting in the 1930s.
- Methyl violet – Discovered by Charles Lauth in 1861, methyl violet can range from blue to purple.
These early dyes allowed purple clothing to be more widely accessible. However, many contained toxic components like arsenic and aniline.
Modern Synthetic Purple Pigments
Today, purple fabric dye is synthetically produced using safer, modern methods. Some examples include:
| Pigment | Chemical Composition |
|---|---|
| Pigment violet 23 | Dimethylquinacridone |
| Pigment violet 19 | Quinacridone |
| Carbazole violet | Carbazole dyes |
These vivid, stable purple pigments are widely used in fabric dye as well as paints, plastics, and other industrial applications.
Making Purple Paint
Painters can mix custom purple paint colors using red, blue, and sometimes white paints. Primary paint colors like magenta red and ultramarine blue are commonly blended to achieve vibrant purples with acrylic, oil, or watercolor paints. Some examples of purple mixed paint colors include:
| Purple Paint Color | Paint Mix |
|---|---|
| Royal purple | Ultramarine blue + Magenta red |
| Violet | Magenta red + White |
| Lavender | Ultramarine blue + White |
| Thistle | Small amount of Magenta red + Large amount of White |
Pre-mixed purple paints are also available including colors like amethyst, byzantium, tyrian purple, and more.
Purple in Fashion and Clothing
In fashion, purple is a color often associated with extravagance, creativity, and spiritual mysticism. Here is a brief overview of purple in clothing over the centuries:
- Ancient Rome – Purple trim on togas denoted high social status.
- Medieval Europe – Purple clothing was reserved for kings, nobles, and bishops.
- 18th and 19th Centuries – Advances in dyeing led to more affordable purple clothing.
- 20th Century – Purple grew popular in counterculture movements and art.
- Today – Deep purples and lavender shades are widely embraced in fashion.
Popular purple clothing shades today include amethyst, lilac, mauve, eggplant, plum, and lavender.
Dyes vs. Pigments
There is an important difference between dyes and pigments used to color fabrics and other materials:
- Dyes – Dyes are coloring compounds that chemically bond to materials like fabric, paper, and leather. Common examples used for purple hues include anthraquinone and indigo.
- Pigments – Pigments are insoluble particles that don’t fuse to materials chemically. They are dispersed in paints, plastics, inks, and more to add color through particles reflecting light.
Both dyes and pigments can produce a range of purple shades. Dyes are best for fabrics, while pigments lend themselves to paints, printing, and plastics.
Light Fastness
When exposed to sunlight over time, many purple dyes and pigments tend to fade or change color. Chemists must try to create shades with good light fastness or resistance to fading.
Here are examples of the lightfastness ratings of different purple pigments, using a 1 (poor) to 5 (excellent) scale:
| Pigment | Lightfastness Rating |
|---|---|
| Cobalt violet | 5 |
| Ultramarine violet | 5 |
| Manganese violet | 4 |
| Dioxazine purple | 3 |
Cobalt and ultramarine violets have excellent 5 ratings, while other pigments like dioxazine purple are more prone to fading over time.
Conclusion
From the snails used to make Tyrian purple in ancient times to the development of synthetic indigo dye, making the color purple has been an important pursuit for centuries. The intersection of light waves that produces this rich, deep color has captivated artists and clothing designers alike.
Today, vivid, affordable purple fabrics can be widely produced thanks to modern synthetic pigments and dyes. These vibrant purples appear everywhere from fashion runways to interior design palettes. The mystical, creative associations of the color purple live on into the 21st century.
From the chemistry of pigments to the history of purple in art and textiles, the making of this unique color is a fascinating intersection of science, culture and our human attraction towards rich hues. While styles and tastes may change over time, purple retains a special place in our imagination.
