I’m getting my wife into working with my local Ghostbusters chapter, and she was wanting me to color-strip a navy blue Dickies work shirt like how some have colorstripped the navy uniform to make it charcoal grey. First time I thought one box of Rit’s color strip powder would do it. No change. Tried two boxes, a little change but still mostly blue. Has anyone else tried doing it to the navy blue work shirt or is it even possible to make it charcoal grey?