These are the best options I've been able to come up with for the QST unit in clue #7, which I wasn't loving. The first (left) keeps the purple 4-patch and changes the QST colors to purple/lavender, for a joining of the blocks. The second uses the constant and yellow in the QST, along with a yellow square to separate the blocks. I'm leaning toward the first option, as I think the yellow separation might detract from the blocks themselves and interrupt the flow of the quilt.