How about cutting a bunch of neutral blocks (maybe a slightly off white muslin or a slightly off white tone on tone) the same size as your 4 patches, alternate the blocks and set everything on point? I'm suggesting just slightly off white for the neutral as that seems to be the prevailing neutral in your colors and it would brighten up the quilt itself as you have quite a few darks and mediums. I can't tell how many 4 patches you have, but I would think you have enough for a small baby or childs quilt (non traditional colors, but would still be great). Set on point, it would add that little extra pizzazz to the whole quilt. Especially if you did a prairie point edging on your border or maybe did a scalloped border. You have a nice scrappy collection of blocks there - would be beautiful.