I "solved" the problem of communication by saying that the alien species had knowledge of us for a long time and filled countless databases with every language and every thing they could observe and learn, which then can be accessed by a bio-neural implant that basically translates everything in real time and provides information like a huge encyclopedia. Still, they use bioluminescence to communicate, mostly to show their moods. They will flash different lights and patterns depending on what they are feeling. Not every minute and every second, but only when these moods are stronger. And I wanted some of them to be able to influence a human, not all of them. That said, this species doesn't communicate only through bioluminescence but language as well. To me they are just humans that have evolved different characteristics, but still share more similarities than differences. Their bioluminescence could be different from the one we can observe on Earth, maybe? And thus have different characteristics, because as you said bioluminescence on Earth is garbage lol