Enforced Electrical Neutrality of the Color-Flavor Locked Phase
  We demonstrate that quark matter in the color-flavor locked phase of QCD is rigorously electrically neutral, despite the unequal quark masses, and even in the presence of an electron chemical potential. As long as the strange quark mass and the electron chemical potential do not preclude the color-flavor locked phase, quark matter is automatically neutral. No electrons are required and none are admitted. 
Krishna Rajagopal (MIT), Frank Wilczek (MIT)