British biotech firm Colorifix has launched Sunlit Clay, a warm, earthy shade for wool produced by engineered bacteria rather than petrochemical dyes, as fashion brands search for lower-impact ways to colour natural fibres.
The company announced the colour in a LinkedIn post on Sept. 29, saying it is available in yarn and fabric and made with its proprietary technology. Colorifix said the shade was inspired by bacteria found in soil and deep-sea sediments. A swatch shown with the post was labelled 100% wool.
Colorifix said wool is defining fashion’s natural fibre movement as brands pivot to circular materials, and presented Sunlit Clay as its answer. The launch extends its biological dyeing into one of the apparel sector’s most closely watched natural fibres.
Based at Norwich Research Park, the company was co-founded by University of Cambridge scientist Jim Ajioka and chief executive Orr Yarkoni. The pair began in 2013 developing sensors to detect heavy metals in drinking water, and turned to dyeing after seeing its toll in Nepal and Bangladesh. The company says it is the first to use an entirely biological process to produce, deposit and fix pigments on textiles.
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The method begins with the DNA instructions for a natural pigment, which Colorifix retrieves from public databases rather than from physical specimens. It inserts them into a bacterium or yeast, then grows the microbes in fermenters on agricultural by-products, much as beer is brewed. The fermenter’s contents are pumped into conventional dye machines alongside the yarn, fabric or garment. Heat bursts the cells, releasing colour that bonds to the fibre, and the remaining cells are washed away.
Colorifix says the process works on cotton, wool, silk, polyester, nylon and lyocell, and fits existing mill infrastructure. It sells fermentation units of 300 or 3,000 litres that dyehouses install on site, along with a concentrate that needs only water. Colorifix says the semi-distributed model, in which colour is grown near where fabric is dyed, lowers emissions, and that training mill staff in fermentation is meant to avoid job losses.
The company’s website lists Sunlit Clay among five primary colours, alongside Oceanic Berry, Oceanic Tide, Solar Glow and Orchard Vale. A colour story on the same page, titled Sunlit Sand, describes a lightfast pigment from soil and sediment bacteria. The website does not say whether that account refers to Sunlit Clay.
Lightfastness is a recognised industry hurdle for biological colourants. Colorifix says it has developed hundreds of colours, but only a few have passed rigorous fastness tests.
Its environmental claims rest on a third-party-verified life cycle assessment of dyeing and final washes on knit jersey made from recycled cotton and polyester. That study found 80% less chemical use, 77% less water, 71% less natural gas, 53% less electricity and 31% lower carbon dioxide emissions than conventional dyeing. The figures do not cover wool, and Colorifix has not published wool-specific data. The company says its formulations meet ZDHC Level 1 conformance and hold OEKO-TEX Eco Passport certification.
Cost, however, remains an open question. Colorifix says it is working toward price parity with conventional dyeing but is not there yet.
Investors are nonetheless backing the scale-up. Colorifix secured $18 million in 2025 in a round led by Inter IKEA Group, with H&M Group Ventures participating, to move from pilot to full commercial production. H&M’s venture arm led an earlier 18 million pound round in 2022.
Portugal’s Valérius Group was its first industrial customer, and it has launched products with H&M, Pangaia and Vollebak. The Earthshot Prize named it a 2023 finalist.
“Ready to test it?” the company asked in its post, inviting mills and brands to trial Sunlit Clay.