Brown is an earthy, natural color that is commonly seen in nature. It is a color that elicits feelings of warmth, comfort, and reliability. But where does the color brown come from and how is it made? The origin of the color brown has a fascinating history and required innovations in chemistry and manufacturing to be produced synthetically.
The Origins of Brown
In nature, brown is found everywhere from tree bark to bear fur. The natural color occurs from a combination of red, yellow and small amounts of black or blue light. It is considered part of the tertiary color palette, meaning it is created by combining the primary colors of red, blue and yellow.
Brown gets its name from the Old English word “brun” meaning dark and dun. The first recorded use of “brown” as a color term in English was in 1000 AD. In nature, brown colors are often muted, earthy and rustic. Different shades of brown come from organic compounds, minerals and soil.
Early Natural Brown Dyes and Pigments
For thousands of years, humans achieved brown colors from natural pigments from the earth that were readily available. Clay, ochre and iron oxides created common shades of brown and yellowish-brown. These pigments were used in cave paintings dating back 40,000 years ago.
The Ancient Egyptians and Romans continued using mineral and clay-based brown pigments. Raw umber, a clay containing iron oxide and manganese oxide, created natural dark brown paint. Sienna contained iron oxides and clay that produced a warm, earthy brown shade.
Animal, vegetable and mineral sources also provided brown dyes for textiles and other uses. Walnut shells, tea, coffee, henna and other plants produced organic browns. Charcoal added black to browns to darken the shade.
Synthetic Brown Dyes – The Chemistry of Brown
In 1856, the first synthetic brown dye was created by chemist William Henry Perkin. While trying to synthesize quinine for anti-malaria medication, Perkin accidentally produced a murky brown substance. The melted mixture produced a brownish dye excellent for coloring fabrics. Perkin patented his invention of the first synthetic dye – mauveine – sparking the birth of the synthetic dye industry.
This discovery showed that synthetic brown dyes could be derived from coal tar, a chemical byproduct from burning coal. In the 1860s, German chemists August Wilhelm von Hofmann and Carl Graebe realized they could extract benzene from coal tar along with toluene and xylene. These aromatic hydrocarbons form the base chemicals to produce synthetic dyes.
Other chemists found that nitrogen-based aniline combined with benzene created azo compounds that bonded to fabric to produce vibrant orange and brown colors. In the 1870s, German chemist Heinrich Caro perfected the synthesis of azo dyes that allowed mass production of synthetic brown textile dyes for the first time.
How Brown Dyes Are Made
Today, brown dyes are produced using sophisticated organic chemistry yet the same basic principles discovered 150 years ago. Here are the primary steps to synthetically manufacture brown dye:
- Extract the key chemical compounds from petroleum or coal tar including benzene, toluene and xylene.
- Combine the aromatic hydrocarbons in different proportions using precise laboratory equipment.
- Add amines or phenols to the mixture to produce an azo compound.
- Convert the azo compound into a stable brown dye by adding special solvents or sodium compounds.
- Test and validate the new brown dye using advanced spectroscopy technology.
By altering the specific chemicals used, the timing, temperatures and many other reactions, companies can produce many varieties and intensities of brown dyes. Modern hair dyes, fabric dyes, paints and other brown pigments go through a similar chemical synthesis process.
Early Synthetic Brown Pigments
While early brown dyes colored textiles and other materials, pigments were still needed to apply color, especially to paints and coatings. Black pigments like carbon black provided a dark brown shade. But brighter, warmer browns were harder to manufacture until the 1900s.
In 1935, chemists at DuPont patented the first synthetic brown pigment – a complex mix of iron oxide and iron hydroxide called raw umber. This replicated the natural umber pigments used since Ancient times. In 1949, CYM pigments developed a modified umber pigment which improved coverage and tinting strength compared to natural umber.
Other iron oxide brown pigments emerged including sienna, mars brown and english red oxide. Using advanced precipitation and calcination techniques, chemists could carefully control the particle size and shape to optimize essential pigment properties.
Modern Synthetic Brown Pigments
A wide spectrum of organic and inorganic brown pigments are now produced industrially. Here are some of the major types of modern brown pigments:
| Pigment Class | Examples |
|---|---|
| Iron Oxides | Raw umber, Burnt umber, Yellow iron oxide, Red iron oxide |
| Iron Hydroxides | Brown iron oxide, Brown iron hydroxide |
| Azo | Toluidine reddish brown, Lake brown AZO, jealousy brown |
| Phthalocyanine | Quinacridone burnt orange, Transparent red oxide |
| Carbon | Carbon black |
Key properties like color strength, opacity, chemical resistance and lightfastness can be customized using layered inorganic pigments, doped metal oxides and polymer-encapsulated varieties.
Advanced digital color matching instruments and software allows pigment companies to produce consistent shades of brown for clients and applications ranging from printing inks to automobile coatings.
Brown Dyes vs. Pigments
While dyes and pigments both add color, there are some key differences:
- Dyes are solutions that chemically bond with substrates like textiles, paper or leather.
- Pigments are solid particles that physically adhere to surfaces through binders and coatings.
- Dyes produce transparent, luminous colors while pigments often appear opaque.
- Pigments tend to be more lightfast, stable and durable than dyes.
For example, a brown textile dye chemically colors fabric brown. But a brown paint pigment only tints the paint itself brown. The pigmented paint coating then sticks to the walls or other surface.
Modern Uses of Brown Dyes and Pigments
Thanks to 150 years of innovations in organic chemistry and manufacturing, brown dyes and pigments are ubiquitous today. Here are some of the most common modern uses of brown colors:
- Textiles – Cotton, wool and other fabrics are dyed shades of brown for clothing, upholstery and carpets.
- Hair dyes – Brown hair coloring utilizes specialized dyes to safely and temporarily color hair.
- Printing inks – Rich warm browns are widely used in packaging, publications and commercial printing.
- Paints and coatings – Brown pigments tint decorative paints, stains, automotive paints and industrial coatings.
- Plastics – Polymer and plastic materials can be colored brown for consumer goods, machine parts and more.
- Cosmetics – Makeup including lipstick, eye shadow and mascara contain brown pigments.
- Artists’ colors – Painters mix organic and inorganic brown pigments to depict landscapes, figures and more.
Brown dyes and pigments continue to evolve using nanotechnology, fluorescent pigments, layering effects and other advanced means to produce attractive, durable brown colors.
Conclusion
The color brown has come a long way from its humble origins in nature. Early artisans relied on minerals, clays and organic dyes to produce earthy brown hues. Today, chemists synthesize countless shades of brown dyes and pigments that color our world. The history of inventing the color brown mirrors the broader evolution of chemistry and industry over the past two centuries. Looking ahead, innovators will continue developing novel brown tones, motifs and effects for design and self-expression.
