The real issue nobody talks about is the salon schedule itself. You got double booked on purpose and no amount of skill saves you when two color clients land at the same time. @lee_reed is right about the pre-pigment but the green also couldve come from hard water or product buildup on her hair, which means a test strand wouldve caught it before you touched her head. What I started doing is telling the front desk I need 15 extra minutes between color apps, and if they cant give it, they book it with someone else. Management loves to say yes to every client until it blows up on you.