Yea, 4th photo is a Electric blue Jack dempsey. I don't personally like them, as they arn't growing nearly as fast a the regular, and don't seem as hardy or aggressive, but mum likes them best out of all my fish, so they are staying.
All my delhezi have similar markings, I put them having dark markings down to having heaps of dark coloured drift wood in the tank, that they like to hang out on. I am wanting to make the substrate black sand to help bring out there colours more, I just havn't found any yet.