Am I the only person who gets confused when 紅茶 comes up with a definition of "black tea". To me if you order 紅茶,I certainly dont expect to get "black tea", and by that I mean I certainly dont expect to get what westerners expect/understand to be black tea.
I suggest it should be called red tea. I am not sure if there is a rule, but generally I expect 紅茶 to taste like oolong, although I expect there may be regional variance.