Go to Dharma acid dyes. They have all the detergents, salts, and citric acid you need. Over 80 colors are available at great prices for 2 oz jars.Great tutorials as well. You can eve get some of that elusive nylon sparkling bunting ( unspun fibers ) there to blend your own sparkle dubbling. If you need to bleach material first, go to your local pool and hot tub supply and get some hydrogen peroxde. Mix it to 20% strength, Be careful. Add strong to weak if you need to dilute. Wear safety goggles, rubber gloves, an apron, etc. Dyes are temp, concentration, material, and time sensitive. From day 1 keep a log of what you try and what works if you want repeatable results. Dyeing and Bleaching Natural Fly-Tying Materials by A. K. Best
Is a fantastic source of information for those who want to do this on a more serious level. With limited sources for natural materials, doing it yourself is fast becoming the only option.