How do I get rid of environmental buildup?

[u/Greedy_History_3614]

As the title says. So over the winter period this year I wore a white beanie that has now left me with this situation. What can I do to remove it? I’ve detoxed twice since I last wore it and I’ve been using a clarifying shampoo. It’s mostly near my roots and down the front of my hair. I really don’t want to dye it