Colour advice help

[laura250]

I have a new client in on Wednesday, she has dip dye hair at the moment with a base 6 she wants to have a base colour of 6/7 and a light blonde and dark blonde highlights so am thinking of doing the base 1/2 6 and 1/2 7 with 6% then for the darker blonde 1/2 8 + 8.31 and 30 vol and for the lighter blonde ash+ and 40 vol then comb the base colour though the packets this is all in L'Oréal does ths sound ok ? Thanks am a mibile hairdresser so any advice would be good