This is a great quilt! I love the brightness, and the optical illusion of it. I would SID around each of the squares that surround each star. Do the red in red and the blue in blue. Where it overlaps the other color, just keep going! It will emphasize the illusion of the quilt, and might be enough with the stitching you have already planned around the stars and the stablizing you have already done to call it good.