I have said it before and will again, it all depends on how your hair grows grey. My family has a gene for not going grey. I, like a number of my cousins, have got well into our 60s before our hair starts greying. I am in my mid-70s now and still predominantly my original colour.
Unfortunately when we do go grey, we develop a ring of grey or white hair round the edge, while the crown of the hair stays dark and quite frankly, it is not a good look, like a brunette angel whose halo has been rammed round their ears.
I am resigned to colouring my hair for the rest of my life. Now, I colour my hair to match the predominant brown colour and later when I am mainly grey, I will be bleaching the brunette hair on the crown of my head to match the grey/white.
One of my uncle's died at the age of 85, the recent photo of him on the funeral service sheet, showed him mainly white haired with a dark brown patch of hair on the top of his head. Even on a man, it was not a good look.