So I have a client with a lot of colour build up coming in on sat morning. I did a strand test on her using bleach and 12%. It only came up to a orange/red. In already quite reluctant to do anything really, I've advised her that it will take time to get lighter as she has so much build up of colour( home colour) i think it's around a 4 with a violet tone to it. Some bits have faded to a 5.shes booked on for a half head highlights, as she doesn't want the expense of stripping it etc. she's got long thick hair, having a "trim" on the day.any advise what I can tone this with that will look good just scattered in her hair , she wanted to go like a caramel colour initially, do basically we r taking her lighter over time.