Even better than the color catcher sheets would be washing the quilt with Synthrapol. This suspends unset dye particles in the wash water so they can be rinsed away.
If the color catcher sheets don't work, try Synthrapol. Sometimes you have to wash several times with Synthrapol to get all of the bled dye out. Whatever you try, don't dry the quilt in the dryer unless all of the bleed is gone; you don't want to inadvertently heat-set the bleed.
Synthrapol is available in many quilt stores, especially those that cater to dyers. It is not expensive.