Until the male pattern baldness thing started happening I had long, fine black hair. Even my pubic hair is straight (not curly or wavy). Now I keep the hair on my head buzzed, but I could still grow a massive pony tail (a common look in Spain, but one I find a bit nefarious-looking). Beard and pubic hair are all salt and pepper these days, but several years ago (may something like 8 years ago?), The Squeeze started buying two different shampoos; one for him and one for me. Over time I've noticed that I no longer have silver pubes or silver hair mixed in with the black of my beard and mustache. Instead, I have blue/silver hair mixed with the black. It's the shampoo. It contains a bluing agent that I don't really notice unless I'm in bright sunlight. Still, it's better than the yellowish color hair tends to turn once one goes gray.
Although the hair is different between me pubes and me head, at least it all matches.