As a longarmer, I first ask the maker if they want the quilting to stand out or the quilt pattern. This helps me suggest thread colors. If you want the quilting to show variegated or orange/purple (the color you want to dominate). If you want the pattern/fabric to stand out I would go light maybe white and back light blue to match the bubbles. This is one of the hardest decisions for most of the ladies I quilt for.