sp = space
Attach color B in the back loop of the chain of the corner loop of the Outside Round.
Headband Row 1: (working along short edge), ch 1, sc in back loop only in same place as joining, sc in back loop of next sc, (ch 2, skip next sc, sc in back loop only of next sc) 3 times, sc in back loop of ch of the next corner loop.
Back Loop illustrated at: http://crochet.about.com/library/blbackfrontloop.htm
Headband Row 2: ch 1, sc in back loop of ea of first 2 sc, sc in first ch-2 sp, (ch 2, skip next sc, sc in next ch-2 sp) twice, sc in back loop of ea of last 2 sc.
Crochet In A Chain Space: http://crochet.about.com/library/blchainspace.htm
Headband Row 3: ch 1, sc in back loop of ea of first 2 sc, (ch 2, skip next sc, sc in next ch-2 sp) twice, ch 2, skip next sc, sc in back loop of ea of last 2 sc.
Headband Rows 4 - 61: (or until desired length is reached) Repeat rows 2 and 3, as many times as needed.
Try the headband on the head of the person who will be wearing it. Add rows, if needed.
Joining ends: When you have the right fit, end off, leaving a strand of yarn for sewing. Hold the right sides together of the two ends (so that you are working on the wrong side) for the joining row. Using a large-eye yarn needle, thread the strand of yarn on the needle and hand sew (with wrong sides facing you) through back loops only of the ends, to join (the front loops leave a decorative ridge on the edge of the granny square, to match the other side).
Turn right side out.