I believe the Reichenow's is a recognized subspecies of the helmeted guineafowl. It is found in Kenya and central Tanzania. I think it could well be one of the African species that is genetically responsible for the blue heads coming out in U.S. bred helmeted guineas.
I've heard of this, and have seen a few pictures of bluish headed guineas here in the U.S., but none of my guineas have that blue coloration. I believe it is a trait that is particular to guinea fowl that come from certain locations in Africa. It could be coming out in some of the guineas...