It has to depend on whether your hair goes an acceptable colour or not and on the condition it's in due to greying. I envy women who retain a good head of strong hair that's silver or white. Mine has gone weak looking and dull. Nothing helps beyond the day it's washed and styled. It's very unflattering and aging. So I have it coloured.
I was interested to see there was a whole 30 minutes devoted to 50+ women during fashion week. Design students were given the brief to dress us. They are probably late teens and early twenties. Some of the outfits were really nice but pretty standard. Others were about the most unflattering, frumpy things you wouldn't dress someone's old grandad in! The worst thing though, was the whispy, long, dragging down grey hair on some of the models. I think grey hair looks great if it's well styled. If it's long, it needs to be in great condition and worn up. There! I've made a statement! 