Scalp bleach to balayage + Wella Color Touch Plus

[Amonavis33]

What is the rule for when you have to fill when going darker? How many shades of depth darker do you need to go in order to have to fill first? Is it 3?

 

[ronray]

Put back it what's been taken out.
If the hair is a 10 and you want to drop it to a 7then you need to use gold and copper in your formula.