My dark secret is revealed at last

The formidable Anna Ford is going grey proudly. Those unassailable Dames Diana Rigg and Helen Mirren wear their white locks with aplomb and possess the kind of easy sensuality poor Posh Becks will never have. And the new US publishing sensation is Going Gray, by Anne Kraemer, who believes we should embrace the ageing process gracefully, accept physical depreciation.

Bad advice, in my view, and not for the reasons you might think. I fear long, painful illnesses, infirmity and death but not age itself. I have never, ever pretended to be younger than I am. Feisty, older women are proud and unbeaten by cruel time and the passing years. We are lucky to be living in an era when you can work, make waves, dress outrageously and seek love way past 60. I type this wearing a pair of hipster Topshop trousers. So why do I still colour my hair? Because it makes me recognisably who I am outside and inside.

Muslim hijabis and Orthodox Jewish wigged women know hair is the most potent symbol of feminine individuality. I was born with brown black hair; my skin is caramel brown and eyes dark brown. Brown is my harmony, my essence. The face, I see, is going quietly older and my body too - though I do what I can to slow down or mask the decline. But my dark hair, the way it moves and frames my face, is - with the eyes and skin colour - a part of my identity. And it has gone very grey indeed.

This summer, just to see, I left it undyed. I still went to parties in beautiful clothes; men still flirted and young women never treated me like a lost Grannie. But I didn't know myself by week 12. An emergency rush to the hairdresser followed.

This isn't vanity or cowardice. Your looks have to fit your sense of who you are. I am alive and passionate. There is a feminist case to be made for wanting to keep age from stamping all over your head, face and body, when inside you are energetic and fresh. If I do let my brown hair go, I will turn dull and it will bring on the arthritis. The future is not grey, not for me, not yet.