Cast on an even number of stitches.
Row 1 – colour A: yarn in front, slip 1 purlwise; yarn in back, K1; repeat until the end of the row.
Row 2 – colour B: yarn in back, slip 1 purlwise; yarn in front, P1; repeat until the end of the row.
Row 3 – colour C: repeat row 1.
Row 4 – colour A: repeat row 2.
Row 5 – colour B: repeat row 1.
Row 6 – colour C: irepeat row 2.
K: knit
P: purl