Thanks for the kind words, everyone. I'm in a rotten mood today (for other, unrelated reasons) and this is helping me beat it!
Carter, the necklace was a 25th anniversary present from Mr. Suz.
Vicki, JAileen pretty much hit it on the head. I have a brother. His hair turned grey over a period of a few months in the past year. He's a few years younger than me. It looked good on him. True, his colouring is not identical to mine and his hair colour was always a bit different, but people would often say we looked like twins, so...not that different.
Then I remembered our parents. I looked up photos of them. It's hard to tell with old photos, they fade or yellow over time...but photos and memory combined persuaded me that while their hair was different and their greys grew in differently, both had looked great with grey hair.
My dad was a childhood towhead whose adult hair was an indefinable colour that I used to think of as almost black...it was actually a kind of charcoal or ultra-ash brown. He greyed at the temples first, then front, then all over and finally turned pure white.
My mum was a honey blonde, then mousy brown (she never coloured), then steel grey, then pure white. At my age she was completely grey and it suited her.
And I knew I was very cool in complexion already, and the blonde was beginning to feel "off" especially as it faded. It seemed to clash with my skin somehow. I felt inauthentic and disharmonious. (Not saying that all hair colour is those things; I firmly support a woman's right to choose! Just that this is how I was beginning to feel.)
If you wait for about 2 months with no colour you can see the base colour very clearly. My strategy was 6 weeks no colour; one set of very ashy highlights with no base colour added, 8 weeks of that, then cut it off.
I think if your parents were/ are grey that gives you a good idea. Ditto a sibling. If everyone in the family dyes, that's trickier. In the end I think the "pattern" matters less than the "proportion." My hairdresser used to say I wasn't "ready" (I think they say 50% is ready) but in the last year I went a lot greyer and knew it was time.