...and just in case you're wondering, all of the sock yarns in the book are Simply Sock Yarn Solids by Simply Socks Yarn Company.
Allison, founder of Simply Socks and generally all-around awesome person, supported my book from the get-go and even helped me choose the ten colors for the socks. I'm a bit scared of color and was worse when this project started. If it had been up to me, I probably would have just run the gamut from Brown to Natural!
I can't say enough good things about this yarn, and I swear it's not just because it's in my book. I made Dee's Moss and Diamond Socks using that yarn and, after 2 years and 9 months of being worn and machine-washed at least once a month (I machine-wash most socks and hang them to dry), they really almost still look brand-new. It's soft, tough, reliable and not too expensive. You don't find all of those things, at the same time, very often. Also, seriously, check out the stitch definition on that particular pair. AMAZING.