From Knitting New Scarves:

Much colorwork in knitting has a clear right and wrong side, but this two-color hourglass-shaped scarf is reversible, and can be tossed casually around the neck without any concern about which side is facing front. The single-color ribbed sections and the neck area are knit flat while the contrasting two-color slip stitch sections are knit around.

Requires US 11 straight needles, and three US 8 double-pointed needles.