There is Babylon 5 episode about the conflict between Drazi of "green" and "purple" characteristic (2x03, coincidently? one of the more important episodes for the overall story arc). Last week I was reminded of this while thinking about Ingress and it's green vs. blue "conflict" (which is wonderfully designed such that taking the in-game fights into meatspace will gain you nothing in comparison to settling them in-game).