It's absolutely an individual decision. Some women look fabulous with grey hair. I can't imagine Emmy Lou Harris without her gorgeous grey hair. Whatever makes YOU feel good is what you should go with.

I'm a natural redhead, so my hair turns white rather than grey. I have a few white hairs coming in but they blend with my blonde highlights. I can't imagine ever letting my hair go all white. I'm terribly pale and I think I would look ghastly with all white hair against this very white skin. Some women can carry it off, though. It's YOUR hair, do what YOU want with it!