I, too, am thinking of a single color (blue) string quilt. I will use fabrics from very light to very dark, but all the same color. Will sew up 4 blocks to see if I actually like how it looks. Yes, I am a "controlled" scrappy gal as well, so the strings will be carefully chosen. (Does this negate the whole premise of scrappy? LOL)
All the quilts posted are stunning. I love, love, love string quilts. My avatar is a 2 color string quilt.