I think it didn’t work for you because your hair had an orange like appearance and blue neutralizes it, thus, getting brown hair. Maybe try bleaching or simply color it platinum blonde along with blue shampoo to get rid of the orange undertones (you won’t get a platinum blonde result, only a lighter brown)

A sucking are such a waste of money, I bought the blue one twice and the green one once and tried them all in my more dark hair and they didn't take at all absolutely no color transfer. I bleached my my hair and it was like platinum and I use the blue again and it turned my hair gray, like not the pretty silver like straight up old lady gray. They are a waste of money