Slip Stitch Knitting 17: Gridlock

PATTERN
Cast on a multiple of 4 sts.
Row 1 (RS): Color A, knit.
Row 2: Color A, purl.
Rows 3, and 5: Color B, k4, *sl 2 wyib, k4, repeat from * to last 6 sts, sl 2 wyib, k4.
Rows 4, and 6: Color B, k4, *sl 2 wyif, k4, repeat from * to last 6 sts, sl 2 wyif, k4.
Row 7: Color A, knit.
Row 8: Color A, purl.
Rows 9, and 11: Color B, k1, *sl 2 wyib, k4, repeat from * to last 3 sts, sl 2 wyib, k1.
Rows 10, and 12: Color B, k1, *sl 2 wyif, k4, repeat from * to last 3 sts, sl 2 wyif, k1.
Repeat rows 1 - 12.