I'm 44 now, got my first silver strand at age 14. My base color is very, very dark brown (nearly black). I've never once colored it, and it's been some variation of a pixie for 23 years.
It's still not totally silver; I have a higher percentage of silver in the front than the back, but it's gradually shifting over time. My eyebrows are still very, very dark, as are my eyes.
Black has always been one of my best colors, and still is. High contrast still works well for me, and I'd say it works best. I've always been better in cool colors, too, and that is even more so the more silver I get (beige, peach, cream, & most pale colors are death on me).
I do find that more saturated colors work a bit better close to my face, and while I"m still drawn to white tops in summer, it *must* be super white and it helps if my skin has a bit of color to it, otherwise I look ghostly.
As for makeup, I haven't changed my routine much over the years, but emphasizing the eyes really does make a difference (I only line the top and wear mascara; occasionally wear eyeshadow) and a bit of cream blush on the apples of my cheeks -- just enough for a 'flush' -- really wakes me up, where for years I never wore blush except on rare occasions. My brows have become really important, too; I don't need to fill them, just keep them shaped, but they make a huge difference. And lip color helps a lot; I think it balances out my face and keeps the contrast going. I never wear anything super dark, a MLBB shade of gloss is best for me.
I am regularly approached by total strangers because of my hair (my husband just laughs about it now). Sometimes people think I'm older than I am from a distance, but then they see my face (I have very oily skin and no wrinkles) and are terribly confused.... Without a doubt it is my signature, and I wouldn't have it any other way.