I have this Red Fin Borelyi. Looking for confirmation on sex. Bought him at about 2" he is now 5". Didn't get much color. Bought as a male. However, the Insignus in the background started going nuts trying to mate with it today?
I'd lean towards a male with the finage and the red showing through. All male tank I assume? At 5inches he should be more colored but if you got him small and there were/are lots of bigger males in tank he may take awhile to color. But looks like a sub dom male IMO with that red coming through. Big females wont look like that. Hope that helps