I ended up not using the black quilting thread. It looked awful. I think there was too much contrast between the cream background fabric and black. It just didn't look right. So, I pulled it out and started over with cream colored thread.
The center of the cream square has an eight-point star in it. Not sure you can see it too well in the photos. I also quilted in each individual piece of colored fabric. It took a little while! = )