Oooh goodness, that is B-E-A-YOOTIFUL! I see what you are thinking about maybe having pink to pick out the colours in the blocks, but am not sure if a different colour border will maybe detract from the stunning 3D effect you have got with the dark/light squares, which is a visual treat!
To me, the bottom looks like it needs another row of the light grey to finish off the pattern, then I think if you still want some pink, you can bind it in pink?
Can't wait to see what you decide to do. I am in awe of this one, it is so lovely.