I do not have grey hair......at least that's my story. My hair is so many colors of blonde and brown that you wouldn't see one or two grey strands anyway.
But I go to the salon for my hair color (had a horrible home experience and swore I'd never do it myself again...I looked like Tony the Tiger). I have not figured out the correct way to state exactly what I want to my stylist. But I think I have it now. So next time hopefully I will get the color how I want it.

My mom has super thick dark brown hair. When she finally started going grey (in her late 40's early 50's) she started using box color (what ever brand is cheapest at the time, usually Clariol I think). So with her natural dark color and then the reddish/auburn color she adds it just looks like she has natural red highlights in her hair. She didn't go mostly grey in the front like most people do. She had speckles throughout her hair so it looks nice. I'm hoping to take after her in the grey hair department. My dad is basically all grey now and he is in his mid 60's.