| | Re: how to make colors colorfast after dying
You probably want to use a fiber reactive dye which are naturally colorfast. I have never dyed feathers, but I dye all my fabrics with fiber reactive dyes. I have tried silk with kool-aid and vinegar but I can't get the color to stay vibrant after washing with that method, they stain pastel more than anything. I had a bit more success with food coloring, but still had some color loss.
I get all my dyed from dharmatrading.com