Soon after I retired I decided to go aux naturelle with regard to colour, and now it is a nice shade of silver grey nearly all over, so no problems about that.
However, I keep my hair short for ease - just brush into shape each morning after shower and that is it. My hair grows (like a week according to one hairdresser I used to go to). Not to complain at my age, so many women are more worried about thinning hair.
Anyway despite regular and often hairdressing visits, I usually 'trim' the top and sides between those visits. I say 'trim' - hairdresser always accuse me of chopping my hair (they are so complimentary, these hairdressers!!).
So, now I am happily trimming or chopping every week or so all over, even the back of my hair and am doing so without any feelings of guilt or worries about comments when I do manage to get it all done professionally again.