I LOVE the pic of Pink in BlondAmbition's link. Other than that, I am not a fan of gray hair on almost anybody. I started going gray in my 20s, and let it go natural when I was 48 or so. It was pretty, in a way, but there is no. question. at. all. that it made me look older. Plus I was heavier then and all I heard was that my celeb lookalike was Paula Deen. Uh... no, thanks.
I decided to go back to blond one day when I was sitting in the dentist's waiting room, reading an article in a magazine about a woman who'd gone gray and written a book about it. There were photos in the article of women who dye and don't dye, and they'd all been photoshopped to show what they'd look like if they were gray (for the dyers) or if the dyed (for the ones who were sporting their natural gray). To my eye, every single one of them (including Emmylou Harris, who does indeed look stunning with her natural gray hair) looked younger and prettier with the gray covered. I made an appointment with my colorist the minute I left the dentist's office, and I've never looked back!
But, you know, Pink. I love her in anything and she is definitely rocking the silver hair!