I wanted the wider border to add to the overall size of the quilt, but I thought it looked a little bit odd to go from 1 1/2" strips in the blocks to 4" strips in the border. So I added that middle border strip made from leftover scraps from the blocks. I think it ties the blocks to the border a little bit more.
It is a totally random pattern with regard to the blues and greens and what fabric is next to what fabric. I mostly like the way pure randomness turns out.
I added the strips exactly how I added the pink strip. I measured the width of the quilt and cut my strips that size and then added them. Then I measured the length and cut my strips that size and added them.
Here's a picture of the entire quilt top, finally finished and ready for the quilter. Finished size turned out to be 68" X 84".