Wish I had an answer -- for you and for me. I buy a lot of fabric online (3 or 4 yards of something I consider a central fabric) and also small amounts of various shades/textures of other fabrics for my stash. However, I get stuck when I need some go-with fabrics for quilt variety. I just have to go to Joanne's or my LQS with the central fabric in my hands so I can get just the color and intensity I need. It's a bother, but I haven't figured out another way to do it.