It's looking really great. The one tweak I suggest is that a few of the blocks have their lines perfectly vertical, and I think they might look better rotated a bit. The seemingly random placement enhances the sense of motion. The blocks are the little yellow one, the turquoise one and medium blue one.
I like Tartan's suggestion to use two layers of fabric with the light fabrics to prevent the black from shadowing through.
I think it's really funny that I mistook your pin heads for a design element in your quilt. LOL!