First, thank you all for your kindness. I know that we have had lots of debate and discussion here on the forum and going grey is not for everyone! I think many of our forum members look fantastic in their (un) natural blondes, reds, and brunettes. (Or blues, pinks, and burgundies, for that matter.) Just to make that clear! My post is more for those who might be considering/ wondering/ ready to make a transition. Not for those who are happy as is.
Aliona, first off, your name should have been one of the first on my YLF inspirations list!! Thank you for asking about teaching. Term is over so I'm not working at the university. The teaching I did in Montreal was with adults, and I'm also mentoring a teen, which is a slightly different relationship.
In North America, grey hair could be a negative with most high school students /teens. In fact, I delayed the transition for a while specifically because my teen daughter was worried about it.
I hope you are wrong about how it will affect the interview process. I think you look so interesting and edgy with the new cut that this should obviate any potential risk. But it's always tough to predict.