Such an interesting thread! I have a couple of thoughts on the matter.
I read a (biology) paper that spoke to why blonde was such a desired hair colour in females. It turned out that blonde most resembled white, so on a biological level it signified fitness/longevity in females, and as such was desired by males in their partner since it would lead to long life in prospective offspring. That said, the contradiction of 'old' hair (grey or white) on a comparatively youthful face and body, trendy hairstyle, and stylish mode of dressing can project all the enthusiasm and energy for life that you need to be seen by society as 'beautiful'.
Being a redhead has been a big part of who I am, and I did not have any colour in my hair until I turned 50 and started to get a lot of white. My hairdresser at the time suggested blonde highlights. I started to be referred to as 'blonde' and I felt like I had lost my identity. A year ago I grew out the colour, and have been natural since November 2012. I am much happier ( and still redder) then I was from 50-52. I have a new hairdresser who has suggested copper penny red highlights, essentially changing the ratio of red to white hair but not eliminating the white entirely (there is no 'grey' per se.). I might try this, but I don't believe I will ever go total coverage/one process.
My mother was a mousey brown, and coloured from the time she was in her 20's. My favourite look of hers was in her late 40's when she had 'every colour' hair. I think it was mousey brown, greying, and blonde highlights. There was so much interesting dimension to her hair. In her 70's, and completely white, she is opting for pale apricot now.
Suz, your features are so delicate and feminine, I think you will be able to carry off the softer brown/white/grey hair colour if that is how your hair transitions. There will be lots of dimensional interest in that. A darker grey, or evenly mixed salt and pepper might not work out so well. Go slow with some transitional highlighting spaced out and without root touch ups. You will probably have your answer by S/S '14. (And won't silver be so much fun with the pale pinks' blues, whites, and greys that were shown on the runways.)