There is no wrong color for this quilt! Really like this grouping of fabrics. Color would depend on how bold you want this quilt. I can even see a narrow lime green inner border with white tonal outer border and black binding. That would be bold to be sure. So many possiblities, you have a job on your hands. When I get to this point, I put some choices together, leave the room for a while and walk back in to get fresh look. It is amazing what you see after leaving the project for few minutes and look with fresh eye. Please share photos when you have completed.