From website:

Knitting this pattern is a joy because as you do the decreases and increases you watch the straight garter stitch section pulled into chevrons. It’s also easy -- just one simple variation to remember creates an unusual effect that looks more complicated than it is. The pattern book recommends using two different yarn colors -- one color for the garter stich section plus one row of the shaping and the other color for the rest of the shaping section. I didn’t use it for this hat because of the variegation in the yarn but it sounds like it would create a fun hat.