Here is one out of my main pond that I posted a while back that I think may be a RESxBG or BGxRES.
It does not show well in the picture, but on the opercular tab where there would be a red margin in a RES this fish almost looked like that area was red but covered with a thin layer of balck. The other thing that makes it look like RES genetics is the mottled cheeks under the eye.
