I, too, think it would be fast & easy to just do a plain color fabric on top & a patterned fabric on the bottom & just sew around 1/4 or 1/2 inch in & let it fray. Let the kids do the decorating on the plain fabric side. This side could be pastel colors & let the kids do what they want. Plus they could do a little clipping to make them fray more. If the tops were different pastel colors, the kids could pick the color they want after you put them together. You could even use flannel for the batting & would make a nicer fray.