I think I’ve come up with my final plan! Except for the corners. For now, I’m leaving them as white.
I’ve decided that instead of two purples, I’m going to use Kona Cotton Solids Valentine. I think it will keep the quilt bright, even using the charcoal background. I plan on completing the blocks in rainbow color order, first the center blocks, then the triangles. I’ll finish with the corners, when I figure out what to do with them. The last block will be the very center.