I have found with mystery quilts that definite colors that stand out against each other are best. Once I tried to "coordinate" my colors on a mystery quilt and ended up with a quilt top (nope, cant bring myself to get it quilted) that was ugly. I have to suggest from experience to not trying to coordinate too much. Go for contrast or the pattern all blends together. That is one reason I choose burgendy, light sea grean, (black and white for the little hour glass). These are colors that don't sit together on the shelf too well, but will stand out in variety.