Here's the problem with these questions. It is impossible to simply eyeball a fully grown adult fish and determine 100% if it's A. labiatum or A. citrinellum. For far too many years, these two species have been crossed by breeders and farms all over the world. Some of these people may not have known the difference between the two while others simply may not have cared.
Either way, the fish commonly found in lfs and chain stores are most likely going to be hybrids of the two species. I don't recall who it was but someone on this site coined the term 'Midevil" for these fish and it's starting to stick. That's essentially how any "Red Devil" or "Midas" purchases from an lfs should be treated...as a hybrid of the two.
Add to the above the fact that other species of the Red Devil complex (such as A. xiloaensis, A. sagittae etc) are becoming more available, there's no telling how much more hybridization will occur with these closely-related species. We may eventually have to start calling them Midexiloittae.
The only way to know for sure is to get your fish from a reputable source. There are many reputable sources around such as Cichlid Connection, Jeff Rapps, Don Conkel, Ken Davis and I'm sure many others