Suede Jacket Discolored From Dust And The Hanger?

I have a blue-gray suede jacket with a purplish discoloration in a line across the shoulders and collar about where the hanger was, which I think is from dust accumulating on it as it hung unused in the closet over the summer. I've tried brushing it without success. Has anyone else seen this from just dust? Any tips on cleaning would be appreciated.