knit in Knitpicks Felici, Blackberry Jam colorway (discontinued)
These are really simple. When the color changes, regardless of where in the round that happens, you begin two rounds of slipped stitches. Then you knit in stockinette until the color changes the next time.
I did the bottom of the foot in plain stockinette so I wouldn't have to step on floats.
It uses an afterthought heel, which is worth the trouble because it preserves the stripes. I was determined to be able to knit these while at Andrew's parents' house for Easter, so I did the heel before finishing the foot so I'd be set for easy knitting. Also, this helps me justify having more than one set of needles in the same size!
I really like this pattern. My love for self-striping yarn is immense, and this is a great stitch pattern to have in the library for this sort of yarn. This pattern also convinced me that afterthought heels are worth the hassle. It really makes the stripes look nicer.