RCSusan

Pics of my one block wonder (hopefully I uploaded correctly), front and back. Back happened because I was short of fabric.

i like the idea of using only your purple blocks, and gradually change colors purple in bottom corner, up to green on one upper corner and blue the other corner, so the eye travels smoothly, transitioning from the dark purple to the blue and green. You could use the blue and green cubes floating in your backing possibly but that is like designing another quilt. Or possibly in a blue or green border if you’re adding one. I think using all 3color cubes is a bit much. Sometimes less is more. But just my opinion.