Welcome to Fishlore, Tunisiano.
I don't know anything about cichlids, but in general, fish can change appearance and/or behavior from being stressed. Sometimes, a particular fish can feel stress even if others are not displaying the same behavior. Stress can be caused by being in a tank that has not gone through the
nitrogen cycle, being in an overcrowded tank, being in a tank with aggressive tankmates, being in a tank that is too small, etc.
It seems like your best bet might be to return the cichlids and have a tropical community tank until you are able to upgrade in April.
Good luck.
