So I've a client that I would say 30% grey who used box dye black. I've been trying to transition to lighter hair.last time did a full head of highlights and kept the box dye colour between highlights just matched the roots up to it .so she wants to go lighter now again , I say highlights are now a level six as I toned them down to a caramel so the blonde black colour would not be too gaudy. So I was thinking instead of a full head of highlights again to finally get rid of the box colour could you take slices in packets and do a root drag say a level 8 on the Grey. Any opinions. How would the pattern of old weaving blend new lightened black pieces.