hi, any advice would be great, I have a lady with a natural base 5/6 she normally has 88/00 and 99/00 on roots and highlights throughout, her hair needs a break from the bleach so we tried a 10/0 with 20vol equal parts, top and sides 60 percent grey, so we need to cover and lift dark areas, its lifted the dark well enough but the grey is translucent, how can I cover and lift please