Nasir Mahmood
NATURALLY coloured cotton has been cultivated and used for thousands of years in ancient civilizations such as those of Peru and Egypt.
While modern cotton is typically grown for its white lint, naturally pigmented cotton provides an eco-friendly alternative by reducing the need for chemical dyes, thereby minimizing environmental pollution. Historically, naturally coloured fibers were grown across Central and South America, Asia and Africa.
In contrast, synthetic fibers release harmful chemicals into the environment and chemically dyed cotton also contributes to pollution while posing potential risks to human health. Although naturally coloured cotton generally has lower spinability, yarn strength and fiber length compared to white cotton, research efforts continue to improve these properties. New colour varieties are being developed through conventional breeding and genetic engineering, which involves identifying and cross-pollinating plants with desirable traits.
Currently, seven lint colours have been identified and stabilized: cream, tan, medium brown, reddish brown, chocolate brown, mauve and red. Brown and green are the most common. Interestingly, in some regions green coloration may arise not only from genetics but also from environmental influences. The colour of stems and leaves, however, does not necessarily reflect the colour of the bolls. Unfavorable growing conditions often reduce colour intensity and even within a single boll, pigment distribution can be uneven with one side more deeply coloured than the other. Colour intensity remains one of the most important characteristics of naturally pigmented cotton. Studies show that pigments usually appear in rust-red or brownish shades, concentrated in specific cell layers. Fibers exposed to greater sunlight—typically those higher on the plant—tend to develop deeper hues, suggesting that light enhances pigment expression. Recent research in China has confirmed that flavonoids are the main pigments responsible for brown cotton coloration.
A landmark achievement in this field was made by Dr. Sally Fox in California, who successfully commercialized naturally coloured cotton under the brand Foxfibre. Since then, the global textile industry has shown increasing interest in these fibers. To overcome limitations in fiber length, strength and spinnability, naturally coloured cotton is often blended with white cotton during spinning. However, fabrics produced from such blends usually have a duller appearance than those made from pure white cotton.
In Pakistan, the plant population per acre typically ranges between 7,000–10,000 compared to the recommended 20,000 plants per acre. This lower density is a major factor in Pakistan’s reduced cotton yield compared to other countries where plant populations usually range between 20,000–40,000 per acre. Chemically, naturally coloured cotton shares most components with white cotton—cellulose, hemicellulose, proteins, pectins and waxes—but with notable differences. It generally contains slightly less cellulose (88–94%) but higher levels of wax, protein and pectin. These variations partly explain its reduced fiber strength but may also contribute to beneficial properties such as reduced allergenic effects on human skin.
In conclusion, although naturally pigmented cotton faces challenges in competing with conventional or hybrid cotton, it represents a promising alternative. With its reduced environmental impact and potential health benefits, it holds significant value as a sustainable textile resource for the future.
—The author is affiliated with the University of Agriculture, Faisalabad.
