Gray looks great! The Navy and Green are not bad but the gray is more neutral and can be used anywhere.
What kind of quilting are you planning on doing on the gray? If it is a pattern that will look better on a continuous band of fabric, then you may want to replace the first border with a bigger border. If the extra seam line in the border won't make a difference in the quilting pattern, then you don't necessarily have to replace the first border.
Good job on the quilt!