Is there a white border (or whatever that background color is) around each block? I can't quite tell on my computer. If so, I think I would trim it to maybe a finished width of about 3/4 in. (after seams are sewn), then pick two colors that you want to pull out from the blocks and make sashing and cornerstones from those 2 colors. Putting the blocks on point may add extra impact. I would just play around with them and see. If they don't have a white (background color) border, I would add a narrow one around each block, making an equal and neutral place to add the sashing. I, personally, would not alternate with solid blocks.