I haven’t researched it, but since you mentioned the ‘rust’ colour, perhaps a supplement that is a good iron scavenger might be in order. I know I’ve read something about this over the last few days, but it was unrelated to what I was looking for so don’t recall where it was. I think it was to do with rogue elements of iron in the brain being damaging or something. I’m also pretty sure it was a mainstream supplement.