I’ll also add, I’ve not raised Blue JG, however, I’ve raised a few blue versions of other breeds. As I recall, the Blue or splash colors are not black as chicks, so you may have Black JG.
Also, all JG have single combs, should have 6 points.
APA standards for Blue and Black JG, things you can see now:
Beak: black, shading to yellow towards tip.
Shanks and toes: nearly black with a tendency towards willow, black preferred (on Blue JG indicates nearly black or dark slaty blue, with tendency towards willow, black preferred)...