mordant problems

[adrian_turtle]

A long time ago, I wore a red shirt with light tan trousers. It seemed like a good idea at the time, but the time was one of those pouring-down rainy days like today. I got so wet that the top part of the trousers went all blotchy with unfixed red dye. Despite the fact that red dyes for natural fibers aren't very colorfast, it hasn't come out after many washings. Various detergents, bleach, stain removers, don't help noticably. After the first few months, I stopped being deterred by the common warning "do not use on khaki," but those aren't helping either. Should I just throw the trousers away? For washing in the washing machine at $1.50/load, I passed the point of cost effectiveness some time ago. Usually it makes sense to wash a bunch of things together, because they are either colorfast, or the same color. But I don't want to wash these trousers with other red stuff, because all my red stuff bleeds red dye and would just make the problem worse. And I don't want to wash them with other light colored stuff and dye them pink. I finally realized I could have just bought new trousers for the cost of washing them 20 times.