This pattern utilizes the kool aid dyeing technique.

I made this sock for a 10 to 10.5” ankle. If your ankle is of a different size, increase or decrease the number of stitches cast on. To adjust your heel flap, just use 1/2 the number of cast on stitches, pickup enough stitches on the heel flap to equal 1 1/2 times the number of cast on stitches, and keep decreasing on the gusset until you reach the number of cast on stitches.

I use the standard Knitty.com abbreviations. For the full list, go here.