Elisabrat, I'd use black and white as your 2 other colors because A. you don't like the mixed up colors, B. black and white will "match" anything and are already present in each block, and C. Depending on how the mystery goes, it might well calm the quilt down for you or distract you from the mix of other colors. Good luck with it and have fun.
I prefer controlled scrappy myself. My one attempt at uncontrolled scrappy made a swift shift to controlled and now it's on my bed
I think I've posted pictures of it before, and at least this link, but here it is again if you want to see it.....
http://www.flickr.com/photos/5800297...7626558897887/