I'm almost 54 and I went from red hair as a kid, to mixed brown as a teen, to full brown, and now I'm going white. I look really old when I have a few days of stubble. Greys started creeping in during my mid-20s, and really took over by 40. I didn't mind it so much on my head, but the change in colour of the chest hair was tough to accept. My arms, legs, and eyebrows are the final lines of defence, and that invasion has begun especially above the eyes.
I have a lot of friends who started to lose their hair even in high school, and they now shave their heads. The rest are similar to me.
So if it wasn't one, it would be the other.
Thankfully none of us has gone with colouring or replacement. I'm of the "let it be" perspective. And I had a hair stylist who called my current shade "Arctic Blonde" and there's not much wrong with that!