London, Dec 12 (IANS) It is the bane of any laundry day – the stray red sock that finds its way into a load of white clothing leaving it an unintended shade of pink.

But a new type of dye developed by British chemists is set to put an end to the need to separate clothing into coloured and whites.

The technology, which permanently bonds the dye to the clothing fibres, also means that colour does not fade from the fabric with age, unlike current dyeing methods.

Most conventional dyes rely upon the dye being absorbed and trapped inside the threads that make up the fabric, but over time these can leak out particularly while being laundered at higher temperatures, reports the Telegraph.

The new method, developed by researchers at the University of Leeds in Britain, chemically bonds the dye to the chains of molecules that make up the individual fibres.

Patrick McGowan, University of Leeds’ chemist and part of the research team, said: ‘We have developed this for use with synthetic fabrics which are made of long chains of molecules known as polymers and are notoriously difficult to dye,’ according to a Leeds statement.

‘Our approach fixes the colour onto the polymer molecules as they are formed so it becomes part of the material itself,’ McGowan said.

Material dyed with this new technique has been tested using standard textile industry tests that require a material to be washed at 60 degrees Celsius alongside a piece of cloth made from five different types of fabric.

‘They found none of the dye leaked out,’ said McGowan.

In many parts of the world where clothing is made such as China and India, the dye is a major source of water pollution.