I agree with Jan on this, after it's done, no one is going to notice the thread, although you certainly could change to a gray thread as suggested, I usually use either white or ecru thread on all my quilts, and no one has said, oh, you used white thread on this purple/blue/whatever. For paper piecing, I usually have my stitch set at 1.3, but if 1.4 works for you, then that's all that matters.