I used another Jane Sassaman print, ombred with dots, as a background. I fussy-cut the pieces to get the shading from blue near the center to most green on the outsides. The blue blends with some of the star fabric on the inside corners, giving it a scuptural look. It reminds me of mitochondria, although it's been years since I've looked at pictures of those! The added benefit of splitting the corner squares and side triangles is that it is much easier to piece this way - no set in corners.
I'm thinking of relatively plain borders, in green and blue.