Will a 10 volume developer cover the gray?

I have always dyed my hair a light golden brown. I would probably be completely gray if I didn't. I was wondering if the 10v would be ok to use. I've always used 20v but would like to use something more gentle like a 10v. Since I am not going lighter, would it still cover the gray? It doesn't say on the 10v bottles, but aren't 10v simply used to deposit color and not lighten?

Will a 10 volume developer cover the gray?
I actually have a 75% grey haired client I use 10 vol on. Its a level 6 (basic brown for non hairdressers.) I have tried 20vol also on her but it fades faster becuase of the higher vol. The 10 vol keeps her hair darker longer in between apointments.
Reply:10 volume will cover the gray. 20 is just more universal for coloring because it is made for lightening but it helps cover grays too. 10 only deposits tho, so if you are going darker then what you are now it'll be fine. but if you are going lighter then your natural color.. then i would stick with the 20V.