In my defense, Tiga and Trigger look very similar. I blame Tsuburaya for this!
We all do. I think it's kind of a mistake for TsuPro to just make Ultraman Trigger. It feels like it was made to be a replacement of Ultraman Tiga for some reason, despite it being a 25th anniversary commemoration of it. Or maybe I'm thinking about this too much.
While we don't know for certain yet, based on some info it seems like Omega will be joining Zearth in redfacedness.
From what I've seen of the new Ultra, he sort of resembles multiple different Ultramen, such as Seven (with the Eye Slugger and a predominantly red-colored body with bits of silver in it), Regulos (with a similar-looking chestplate), a U40 Ultra (with an oddly-shaped color timer), and Z (with the head shape and eye textures, as well as the red mask from Beta Smash).
I mean heck, he'd probably be related to Z himself. Either as a distant relative, or something I dunno.