I started getting greys in my early 20s and so started highlighting in my late 20s. After highlighting, and then full head highlights and lowlights, for a long time, I switched to coloring it myself at home which saves a huge amount of time and $. I just consider it one of those basic maintenance things so I doubt I will let it go grey for many years yet. Maybe when I'm in my 60s? I'm 48 now. There must be an age where your general appearance catches up to your grey hair so that the grey hair isn't so "aging" anymore??