private function rebuildColladaMaterials(d:DisplayObject3D, matList:MaterialsList):void {
	for each(var child:DisplayObject3D in d.children ) {
		if ( matList.materialsByName[DisplayObject3D(child.parent).name] != undefined ) {
			child.material = matList.materialsByName[DisplayObject3D(child.parent).name]
		}
		rebuildColladaMaterials(child, matList);
	}
}

Replacing materials in a DAE instance can be a real pain in the ass. This function iterates the children of a DAE instance and assigns materials by node name from MaterialsList.

Replace materials from DAE scene

ActionScript 3