Cast on with Color C and knit one row.
Colors A, B and C.
Repeat rows 1 - 12.
Row #SideColorBegin RowRepeatRepeat From *End Row
1RAk1*p1, k1 in the row below*k1
2WA*knit* 
3RBk1*k1 in the row below, p1*k1
4WB*knit* 
5RCk1*p1, k1 in the row below*k1
6WC*knit* 
7RAk1*k1 in the row below, p1 *k1
8WA*knit* 
9RBk1*p1, k1 in the row below *k1
10WB*knit* 
11RCk1*k1 in the row below, p1 *k1
12WC*knit*