The famed fashion designer had already undergone the dramatic transformation at her Paris Fashion Week show. When she took to the runway to take her bow, however, she hid her new style under a feathered headdress.
Vivienne showed off her new 'do when she joined a protest in her local borough at the weekend.
The 72-year-old joined comedian Mark Thomas and artist Maggi Hambling on Lillieshall Road in Clapham to oppose the sale of long-standing house co-operatives.
Her hair was completely white, but Vivienne kept a touch of red with flame-coloured eyebrows.
"Vivienne cut her hair as we must all wake up to climate change," said a spokesperson for the designer.
"And secondly, she wanted to cut the red out for a while and have it white – to show that she's proud of her age."
The eccentric designer has been campaigning against climate change for many years.
In February, she announced that she would not be expanding her business in order to focus on backing Greenpeace's work to protect the Arctic.
She also vowed to donate £1m of her wealth to fund green projects and recently spoke out against throwaway fashion.
"Instead of buying six things, buy one thing that you really like. Don't keep buying just for the sake of it," she said.
"Don't invest in fashion, but invest in the world."