ALong those lines, a few years ago I suddenly developed a grey streak after some trauma in my marriage. My friend's mom called it a "shock of grey" (a term from her generation and at least the one above it) and to her there was no question it was from the recent "shock" in my marriage.
I since developed another one (same reason), but then a year and a half ago got willing to work thru my issues and become honest with myself... the second streak is gone and the first one is going away.