It'sthat simple
Paint one side of the standing collector with 2 - 3 layers Magnetic paint and let it dry. Apply Board paint once or twice on the fronts of the two collectors, paint the other sides and the magnetic surface red or blue as desired. First prime the lid of the storage box and the inner surface of the scrap paper collector in grey and paint it silver after drying.
Tear off individual sections from Napkin , remove the white layers of paper and stick the printed layer onto the lid with Napkin varnish . Glue masking tape around the lid and, if you like, also on individual areas.