I would suggest adding a border as others have stated to the quilts that would look o.k. with an addition, perhaps add a flange of some color to corordinate with the new border and the quilt. Another suggestion that has also been posted is to use some netural color plain bedspread or king size sheet and lay the smaller quilt on top of that, perhaps add some type of border to this bedspread or sheet that might work with most of the quilts in color, or just use the sheet or bedspread. You could shange your decor as often as wanted this way.