It is unlikely that you have herefords. 
I have had mice that were Irish Spotted (proven with test matings) that had white markings from a headspot, white feet, white belly, half white tail to a full white collar and blaze, white stockings, white belly, and half white tail.http://www.informatics.jax.org/javawi2/servlet/WIFetch?page=markerDetail&key=18673