Lots of great comments since I last posted!
I have some not-related to $/time/roots reasons for wanting to try going grey now (mid-40s/20+years of dye/~ 40%).
One is that I'm *not* a hair color "experimenter" and so I've always been a brunette. The idea of *not* being a brunette feels really weird, so I want to ease into it while I still have dark in the mix. [I should say I'm easily confused when actors have different hair colors film to film, ha.]
Another is that I've been told "oh you look too young to let the grey show" and because I *felt* really decrepit with health problems, I didn't want another signifier of old. Now that my health is much improved, I'm ready to have the contrast of "older-signal" hair with somewhat "'younger'" face.
It helps that there's a cultural shift underway for grey on all ages, for sure. [Edit -- And I DO think this will impact the workplace ageism.]
Which actually kind of begs the question -- because of all the hair coloring, what age DO people [general] think is appropriate/average for grey/silver/white? Seventy vs 50? I wonder.
And agree with the comment upthread that to most truly young people (under 25) there's pretty much just "old" and "really old" hahaha. They aren't much for nuances that hair coloring provides.