Try using only one background piece and then use only blues or greens or reds. It will be matching and scrappy all at the same time. Quiltville.com has on called my blue heaven that is all blues and creams. Instead of mixing up the cream just use one fabric. I think it is ok to use the same fabric for background and all the rest scraps. Good luck. I have been doing only scrap quilts since November and I love the way they turn out.