Not likely a color morph. From what I am told, the only other fish caught in that river were Cutteri and Robertsoni. No other Parachromis were caught. It was speculated that it might be a natural hybrid (Managuense/Loiselle). But if that were the case some of either of these fish would have been collected (or seen) as well. They weren't.
Rusty Wessel indicated in an e-mail I sent, that they knew of an unknown Parachromis. A German crew had collected them in the Rio Danto the year prior. So it looks god that it is the new Parachromis they spoke of. He was convinced enough to bring back an adult pair. The picture of the adult male is spectacular.