When I waas around 40 (30 years ago) I got some grey in the front, but did not want to color all my hair. Ever since I have used Mennen for men's beards. You just have to put it on with a little brush in the front. Since you can just use enough cream, the box lasts about for 3-4x. Very cheap.
Once in awhile I also use it for my eyebrows.
Still using it, my hair so far has not gotten more grey. Just lucky I guess.