EXPERT CROCHETERS! How do I crochet a scallop edge for a baby blanket?

To give you an idea of my project, it is a 7sq by 7sq granny square baby blanket (49 squares total). Each of the squares has a 1 inch border of white and all are joined together by white. There are vertical ridges on each side where the yarn has been joined. My colors are: white, purple, pink, blue, yellow, and green - all pastel. I want to incorporate all of the colors into the border. Any fun ideas that are fast?