I don't think a scrappy quilt can't ever be too scrappy! I see a lot of "controlled" scrappies...like using just one or two color lines...and they are nice too. I think that the greater contrast between the lights and darks can create nice patterns, but what is light or dark depends on what fabric is next to it. You only have to please yourself. I have a collection of scrappy quilt books and when I want to do a controlled scrappy, I look through them to get ideas.