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.
The Loopy Love Blanket is so fun to make! The pattern is easy to memorize, the stitches just fly by, and the end result looks way more complicated than it should. And in 3 colors, you can change colors every row and never have to cut the yarn!