Hi, you could try washing the quilt with Synthrapol, which is what is used when dyeing to remove excess dye from fabric and fleece. Not sure if you can buy this from a shop. I got mine on ebay. Most good shops will sell colour catcher sheets or similar.
Red is the worst colour for fabric bleed, closely followed by black. so I always test for dye fastness on them. You don't have to wash the whole piece before you start a project. I generally snip a small square, measure it, and then give it a good scrubbing in really hot soapy water. After drying this will not only show if the dye has run but if the fabric has shrunk.
Hope this helps, Suzy.