I absolutely appreciate the feedback and the conversation; I really didn't intend for this to become a discussion focused the Twilight People, they're a whole different thing (for starters, assumptions made about how humans react to / interact with the world or their culture have to be questioned, the Zath aren't human) but the brainstorming has been really helpful. Which is not to say we should stop, but I also want to get back to the Choumin as well.
So, getting back to my last post on that:
For the Choumin, I'm finding the idea of multiple local and regional cultures having been subsumed into the greater culture pretty appealing, especially with some of the suggestions you've all been kind enough to post, and particularly some of the stories that brian333 has posted.
Not sure if I want to do a single ethnic appearance tendency, or multiple. What I originally had in mind was dark hair, vibrant eyes (hazels, greens, blues, etc), and "cinnamon" skin tones (I need a different descriptor for that, evidently some people find food-words for skin-tone offensive, and I'd rather just avoid that mess entirely). Generally having trouble describing facial structures without sounding clichéd.
I think that their approach in bringing the islands together has basically been "Hello, we'd like to build a town here and trade with you, I'm sure there's lots of stuff we could offer each other." Of course, sometimes this is said with their big ships offshore and a Storm God priest/ess standing just behind and to the side of the trader.
So what seems better as a starting point, before the Choumin / Storm People established their empire? A single overall phenotype with different cultures spread out across the islands, or multiple phenotypes partially matched with the different cultures/subcultures?