If we are going to use only coloration to detemine the ID of a fish I could see the arguement that it is a yellow lab. Black with yellow, but since it is too elongated to be a yellow lab, there is no reason to get into the genome discussion of labs. Also, on that note, not all genes are visible expressed in an offspring. So it may in fact not be a purebreed lab and get fry that looks like a lab, when mixed with a purelab.