I was hoping people would have some ideas...This is my idea:
Reduce the 1st pink border to 3 inches wide
Reduce the rectangular squares to also 3 inches wide, but add a 2nd row in a running bond type pattern
Add another pink border that is 3 inches wide.
I completely concur with this idea. The most important of it would be adding another pink border to stop the rectangular squares. As it currently sits, they seem to go off to la la land. This is exactly what I would do as well.