text: If each quark is represented as , with color index  taking values 1, 2, 3 corresponding to red, green, and blue, and flavor index  taking values 1, 2, 3 corresponding to up, down, and strange, then the color-flavor-locked pattern of Cooper pairing is 
  This means that a Cooper pair of an up quark and a down quark must have colors red and green, and so on. This pairing pattern is special because it leaves a large unbroken symmetry group.