I am not a yarn person (yet), but I buy a lot of silk scarf blanks and other things at dharmatrading.com. I love them. They have a huge variety of yarns, but they aren't colored. However, you can dye animal protein yarns (including silk) with KoolAid, which I've started doing with silk. If you like KoolAidy colors and cheap, nontoxic dye, it's pretty cool.