Glenn Apiaries has a page of Honeybee Geneticshttp://www.glenn-apiaries.com/principles.html
The queen is a cross from her mother and multiple fathers.
The drones are pure for the mother (unfertilized egg).
The drones will be as pure of stain as the mother was?
I've seen hives with pure looking ITA drones, pure looking NWC drones, and I've seen hives with crossed up drones between the ITA and NWC.