The black lapets on the dorsal fin rule out Guianacara geayi and G. sphenozona.
The fact there is a bar rules out G. oelemariensis, and the fact it's not a wide bar rules out G. owroewefi.
That leaves either G. stergosi (aka Rio Caroni) or G. cuyunii. If the bar fades as they get older or if a spot shows on their flank when stressed, it's the G. stergosi. Which is the more likely of the two, it's the most common Guianacara in the hobby.
Almost all the Guianacara are sold as geayi, but it is rarely found in the hobby. Yours are 100% not geayi though ... not only does it have the black lappets on the dorsal, but it has a thin bar instead of wide. Double disqualification. :thumb:
Kind of like how a lot of Geophagus are sold as surinamensis but practically zero of them actually are. It usually stems when all the various species were just throught to be a single species with regional varients, before being split up into differant ones.