Start with 3 colors. Each block is 9 stitches so for however wide you want the blanket, count in 9 to get your foundation (always make it an uneven number of "blocks) eg: 19 blocks(makes it about long) stitches then add 4 sc for the foundation row.
This beautiful afghan is made using granny and filet square design patterns. A total of 61 squares made using a DK-weight yarn complete the design. Finished afghan size is square. Previously published in When Granny Meets Filet crochet patte.