I also noticed some bright orange fish in the background. If they were sold as Africans they are most likely Red Zebras. "Metriaclima estherae" They also can be a bit on the aggressive side. A 50g will be barely big enough for them. There is also the the possibility of cross breeding between them and the Cobalts and they definitely will cross with the yellow labs if you get them.
If you end up with hybrid fry please keep them in your tank or destroy them. Heaven knows there are already enough "mixed" Africans on the market these days

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