A scrapy string quilt does not have to match anywhere. The colors can be random, if you don't want to plan, and the strings can be tapered alot, none uniform. And it doesn't have to start in the center. I've seen some pretty wild ones. The southern black quilts have been documented in several places, like the Gee's Bend Quilts, and their color combinations, you cannot even dream up........all gorgeous.
http://www.quiltsofgeesbend.com/quilts/
http://www.mfa.org/exhibitions/sub.asp?key=15&subkey=498
http://www.auburn.edu/academic/other/geesbend/explore/index.html
http://www.shellyquilts.com/geesbend/
http://www.omart.org/galleries/exhibitions/GeesBend/geesbend.html