Spread out the comforter in front of you, making sure there are no wrinkles or creases in it.
Place a large stencil over the center of the down comforter. A 12-by-12-inch stencil of any design is adequate.
Fill the cutout areas of the stencil with fabric paint colors of your choice. Fabric paints are permanent and don't wash off. Apply the paint so that it is about 1/4 inch thick. Let the blanket dry for about 20 minutes.
Select crocheted or knitted rosettes from a craft or hobby supply shop. Apply a liberal amount of glue to the backside of each rosette.
Press the glued side of each rosette firmly against the bordering of the down comforter. Do this around all of the edges using as few or as many rosettes as you want of any color.