* Chain 3 (this is your first trc), trc in every next chain. Don't cut of yarn at the end of the row.
* Change to color B. Secure yarn to first stitch of the second row and chain 1. Sc in next 3 stitches. Now put your crochet needle in the next st of the first row. Pull up loop of yarn.
Sc in next four stitches and pull up loop. Repeat until end of the row. Cut of the yarn.
* Chain 3 of color A (this is your first trc), trc in next three stitches, *skip one stitch (this stitch should be above the pulled up stitch), trc in next four stitches*, repeat * * until end of row.
* Change to color B. Sc in next four stitches. Pull up a loop in the 'eye' of the loop you made two rows ago. Repeat until end of row.
* Repeat pattern until you have fifteen rows of both colors.