A while back I purchased a skein of sock yarn with cool colors. The promise of the yarn is that it is dyed in such a way that stripes would magically appear as you knit. It's not new and I have seen other knitter's finished projects, so I know that it works. You can see the colors in the skein, but, it really just looks random. But I am still amazed to see it happen before my eyes as I knit these socks. I'm using a basic sock top-down pattern, found here, since you don't want to lose any stitch patterns in the color changes. One skein should be enough to finish a pair of socks.
The yarn is a blend of cotton, superwash wool and nylon. It's not the softest yarn to work with, but I'm sure that it will make a durable pair of socks.