Is 20 volume peroxide right to go with Wella color charm (Very dark brown) hair colour?
My natural hair colour is dark brown almost black according to the whella colour chart the Wella very dark brown 211/2N is the closest match to my natural hair colour.

The majority of the new hair is still dark with lots of grey dispursed throughout that needs to be covered. I have about 3 inches of new growth to cover.

I want to make sure is it ok and safe to use 20 volume developer/cream peroxide with the wella color charm hair colour to cover my roots? Is this the right volume to use as I do not need to lighten my hair could I get away with a 10 volume?

20 volume peroxide is correct. 30 volume is used to make hair much lighter as well as 40. but 10 volume … i have no idea what that’s for, i’ve never seen anything in a beauty shop that uses 10 volume. but yes, use 20. good luck!

hair Color?
I was just wondering if an 8n on the hair color chart is pretty light. If I do this color will it look really light or darker than just plain bleach.

8N is considered light blonde but much darker than bleached to platinum… if you are using it on natural hair color then you must consider what your natural level is first ( i.e. natural chestnut brown hair is a level 3 or 4 with warm highlight using a level 8N with the correct strength developer will end up as level 6 or 7 redish brown/brassy) … store bought products can only lift natural pigment 3 levels at most but usually less… and using an N series ( N denotes neutral) then you are not being provided with any drabbing so the results will have red or gold ( brassy) undertones… if you are using over previously lightened hair then you may flatten out the color… if the hair is porous you can bet there will some drabbing as well
I think you should go to a colorist and have a consultaton before you make a mistake
How To Read the Ion Color Brilliance Color Chart