I agree that it's H nicaraguense.
Here are some shots to compare.
1st some young nics, colors may very according to ancestral catch location.
Someone suggested Gymnogeophagus balzani, so here are a couple of balzani males to compare.
Although they may seem similar, the shape of the mouth is a very distinctive difference between the two
And because Isthmoheros tuyrense is seldom available, except thru specialists, it is doubtful it could be that species, along with a very different shaped mouth, and body (much more Vieja like). It was thought at one point to be in the genus Vieja.