Actually it’s super confusing because the champion that was marked as the blood DK version of Kolitra is now Nazgrim, and Kolitra is now frost: http://legion.wowhead.com/champion=599#championnpcs
I mostly see spec as a game mechanic anyway. For example: Tev likes blood magic, but can do frost magic, and is actually quite adept at unholy through necromancy, but likes stabbing dudes more than he likes raising dudes.
To be fair, Tev would actually look at you like that if you asked him about this.