One of my small groups has a challenge right now. We each picked one tone-on-tone fabric we really liked and purchased enough to give everyone else in the group (5-6 people) a fat quarter. We then choose one print and up to three more fabrics that aren't neutrals, then as many neutrals as we want. The chosen tone-on-tones include some of yours: 3 purples, a red, and an orange. My print includes yellow and green as well, so quite an overlap with your fabrics.
One of the books I own, "Tessellation Quilts," has a quilt with diamond blocks and black rick-rack along the seam lines. I'm thinking I'll be doing that, as part of the challenge is to try something new, and I've not worked with diamond blocks before. The effect is somewhat like stained glass.
I look forward to seeing what you decide to do!