Thank you all again, for the kind words!
I selected the fabrics myself. I started by choosing fabrics that said to me, "am I blue, or am I violet?" Then there were some purples that just grabbed me, so I had to get them, and I had a beautiful cobalt blue fabric just waiting for something special, and I couldn't leave it out! Finally, I had ordered some reds, whites and blues for another project, and one of them turned out to be too violet for the R/W/B project, so it was added into the selection. I believe I ended up with 17 fabrics. It probably would have been easier with 20+, but I don't have very many places to shop (and see the actual colors), nor do I have a big fabric budget.
I like the idea of metallic thread, however, I might like to sell it, and I think I want to be careful about how feminine I make it. I'd like it to appeal to either gender. My long armer thinks she would go with a variegated that will blend with and compliment the fabrics. Other input on this subject is welcome.