Pops of Rainbow Throw

4 columns of 5 squares (total of 20 squares) in two colors are worked bottom to top and then put together to make up this throw. The entire throw including borders are worked using 2 strands of the yarn. While the 5 squares of each column are joined as you go with two rows of the pattern using black yarn, each column is joined to the next column with single crochet using black yarn. To finish, a border is worked at the CO and BO edges with only the remaining VIBGYOR colors. The right and left sides of the throw are finished with a 2-row crochet border with black yarn. The first and last stitches of every row for each square is in garter and forms a neat border.