I've been breeding Blue Dempseys for a couple of years now and have literally hundreds of Blue Genes in my tanks... Although I've heard a few people claim they can tell them apart, I sure can't...
There is another current thread in this folder "post pics of your female Dempseys" (paraphrased) where this has been discussed.
So I am not saying it isn't a Blue Gene... I'm just saying we cannot tell by looking at it... the only way to tell is to breed it with a Blue... or a known Blue Gene...