Ok so no aurals!
If you see a ECAM or EICAS ie, "eng fire" or "apu fire" you should act on it if you see green or red, you should be reading the warning message that identifies a fault to confirm you are acting on the correct system or eng etc. As you are probably aware Ecam gives you actions to follow when faults like eng fire occurs.
If you dont have ecam/eicas, warning and caution annunciators show there is a fault whether the person see's red, amber, green or any other colour.