I have started using it recently, twice now
I have been going grey for years now, since around 22, but lately it just stopped,
I was looking forward to my 'Philip Schofield' in my 40's, but no, just a salt and pepper mess, that was winding me up.
with patches of heavy grey and other areas, nothing or little
so I got the mid range one, and used it, 10 mins later, bang it was brown,
but too brown, so next time I started with the lightest one, and it looks very natural.
so my advice would be, go for it, but start with the lightest shade, to see what you think,
you can always go darker later.
and ignore all the 'silver fox dodger' comments, this area has always ben up for a laugh, nothing would be said if you decided to get blonde highlights