Here's the second yarn list recommended for colorwork so far. I added all the Elann and Knit Picks alpacas I like for stranded color knitting and a few others. It has occurred to me while doing this that I really don't have a lot of experience using non-wools for this purpose. For instance, I don't think I've ever used silk or a silk blend for two-color knitting. I've had some disasters with cotton and superwash wool though.
Fingering Weight
Dale of Norway Baby Ull superwash wool
Blue Moon Fiberarts Socks that Rock Medium Weight
Knit Picks Essential (wool/nylon)
Elann’s Peruvian Baby Cashmere
Elann’s Sock it to Me 4-Ply nylon/wool
DK/Sport Weight Rauma Pt5 Per Tryving wool/nylon
Blue Moon Fiber Arts Socks that Rock Heavyweight
Elann’s Pure Alpaca Fina
Knit Picks Andean Treasure (alpaca)
Crystal Palace Yarns Panda Cotton Solid (bamboo/cotton)
Worsted Weight Green Mountain Spinnery Mountain Mohair (mohair/wool)
Elann’s Peruvian Pure Alpaca
Anyone else have any recommendations? I'm sure I'm missing more sock yarns but I haven't used many of the newer brands for colorwork.