Hairline has a caddis orange, maybe LRO can get one for you. I'm not sure about dying a skin that has already been tanned? I just don't know enough about the tanning process that they use. The salts or whatever they used to tan the hide might have an adverse affect on the dye bath. I'm just not sure. I might pluck the feathers I needed and dye a patch of them. Take a look at this website it has some good information on processing material yourself.
"Have no fear of perfection - you'll never reach it."