I recently did a quilt just like this but the colors were primarily in purple and green. I chose to sash it, as the blocks were so busy with the different fabrics. I used fabrics that went through all the blocks and sashed it with three fabrics. I sewed width of fabric one inch strips of dark with design, middle was turqoise with little design on it and then I repeated the first one. It really pulled the quilt into a different look than doing it with out the sashing. When I quilt it, I will post it here.
If I had to choose for you, I would go with the yellow one. Keep it vibrant.