Hello! I have bought two dyes by colour freedom in the shade metallic black and silver grey in the hopes to do half black half grey hair, my hair is currently a light peach colour and light blonde in most areas too, I intend on bleaching my roots before putting the dye on, should I also lighten the peachy sections too or will the black and silver dye cover it as it seems high coverage from the reviews and videos I have looked at :)
Black will be fine but the peachy is'nt light enough in my opinion. sometimes we can cover what is their but after a couple of washes it starts to peek through, grey over what you have now will be a dusky peach kind of colour I think. Their is an article about dying your hair grey on this site. It's recommended that your base be very light.
Black yes and gray no. A base hair color of the inside of a banana peel is strongly suggested before dying the hair silver or gray. The red, orange, and yellow in the hair know will negatively affect the outcome of the gray semi-permanent dye. The half of the hair that will become gray suggest lighten.
These are my suggestions and opinion.