Zeros at Saipan, May '44

[Pathfinder]

I'm wondering if anyone can help with this question:

In May of 1944, taking off from Saipan to intercept U.S. aircraft overhead, what would have been the likely model of Zero, its unit, insignia, and colour scheme. I know a Zero was the aircraft involved and witness accounts say that it almost looked black, although was probably a dark green?

It's a tall order I know, but perhaps someone can answer all or part of it.

Thank you