This hat is worked in stockinette stitch and reverse stockinette stitch. To work in more than two colors, on hats with 30 or 40 cast on stitches, alternate the second and third colors with color (A). For hats with 35 cast on stitches, alternate the three colors (see red, yellow, and blue hat.)
The yarn used is DK weight (5.5 sts = 1″ on a US 6) and worsted weight (5 sts = 1″ on a US 8 and 4.5 sts = 1″ on a US 9). See specific sizes (infant, toddler, child, and small, medium, and large adult) for yardage requirements.