it somehow reminds me of the "het daddy" gene. whats the ancestry, how far do the records go back? maybe you got something called "lesser platinum" or "platty daddy" in the bloodlines.

(its the weakest gene in the BEL complex, its a codominant, WOBP falsely calls it a dominant, the heterozygous version is indistinguishable from a normal, even the super form is quite unremarkable. the supers are just a few shades lighter than normals, and you can see a little bit of BEL influence. but it strongly interacts with lesser/butter. if there is a true platty daddy in the ancestry, the ones that get the "het daddy" gene instead of the "lesser/butter" gene can easily be re-labeled or mislabeled as normals. its conceivable that you, by random chance or because of genetics in the ancestry you dont know, hit a true platty daddy. im putting this in brackets because im speculating.)

anyway, the one on the left is definitively a keeper. thats what selective breeding is all about, the absolutely best of the best you produce is what stays with you. oh, and, repeat exactly the same pairing, you could get another one. if my speculations are right, repeating the same pairing would continue to give you clutches with a 25% chance to get another one of these. it would mean that your "normal" in fact carries the almost invisible "het daddy" gene. also, repeating the same pairing will help to figure this one out, and if its a gene like the "het daddy" or some other stealthy gene that interacts with strong BEL genes, once you figured it out you can produce more of these at will in the following generations.