Borrowing a page from the K1B Inside-Outside Scarf: two colorways, changed every row. This requires either DPNs or a circular needle:

Work one row according to pattern (Right Side) in colorway A. Slide work to opposite end of needle. Work next row according to pattern (Right Side) in colorway B.

Turn. Work next row in A according to pattern (Wrong Side). Slide work to opposite end of needle. Work next row in B according to pattern (Wrong Side).

Turn. Repeat these four rows.

This little bag was my personal favorite. :)