I wouldn't worry about it. It looks fine just as it is. I think you are just too close to it at the moment. If you have already sandwiched it and have started quilting it, I would just let it be. That being said, I sew with white a lot, and if I use the Warm and Natural that comes in white, the seams don't show...in case that helps.
Beautiful quilt, by the way!!
Dina