Its not a one-size fits all.
Take me as an example. In my early forties I read a mumsnet thread about this, took it to heart, and started having blonde highlights, in anticipation of going lighter as I got older.
I kept doing this for about 7 years. It didn't suit me. I've got a natural "winter" colouring, i.e. very dark brown hair, very pale pinkish skin, blue eyes. The warm tones of the hair looked really brassy on me. I eventually went back to dark brown and everyone said I look so much younger. I have got good skin for my age (early fifties).
My hair isn't yet even close to proper grey or white, its salt and pepper, and I really hate it. When/if it goes proper silver i will switch.
Also, many women of South Asian origin have dark brown/black hair and brown eyes, and they look lovely with dark brown hair.
Its an absolute pain doing the roots every 6 weeks. I have to, because the sideburns are white - it's a bit too Addams family. 🤣 I have considered dying it white, but I dont think it would actually work.