Thank you all so much! I pieced and quilted the 4 background pieces first. Then I completed the color wedges using fabrics from my stash, making groups of 4 or 6 wedges. Of course the wheel wasn't flat when I started attaching all the wedges together so I had to sew a little more seam here and there to flatten it. Then I machine appliqued it onto the background. It wasn't a particular pattern.