1. A lush tropical island, with an "advanced city" in a central location, with the intention of preserving the natural wonders around it. But, it shouldn't necessarily correlate to a western ideal of an "advanced city". Instead, it should reflect alternative advancements made by the Amazons during the thousands of years since their isolation. Sure, the Amazons may be first and foremost warriors, but they're also artists, architects, scientists, designers, landscape architects, etc.
I guess, kind of a mix of these designs:
http://images-cdn.moviepilot.com/im...onder-woman-s-home-themyscira-jpeg-119616.jpg
http://comicsalliance.com/files/2015/07/wonder_woman_earthone-spread.jpg
http://images.imperialnetwork.com/data/Harnaidan.jpg
But, that seems pretty unlikely if the DoJ New Mexico set was Themyscira and some of the shooting locations for Wonder Woman's stand-alone film also indicate that Themyscira won't be an obviously advanced nation and will instead more closely resemble the New52 version of Themyscira.
2. If the Amazons on are on their secluded, protected island, then I could see them dressing in simple chitons, tunics and vests/pants (like the Persian female warriors), probably based upon their personal style and day-to-day activities. I don't think they would wear armour all the time. Solely based on Wonder Woman's armoured costume, I don't think they would have any body confidence issues and if the temperatures are warm, then I could see the clothing being on the "minimal" side.
The colours will really depend upon the nature of the Amazons. I would like to see them as an idealised, future civilisation. But, it seems like we're going to get more of a battle-hardened "warrior" class of people, so I'm guessing that their clothes will be relatively practical and simple colours without any real personalisation or decoration for the sake of aesthetics. Once again, possibly something similar to the New52 Amazon costumes.
Diana seems to have embraced various colours and styles in her "Diana" persona, but I'm not sure that is something that simply reflects fashions on Themyscira or is something she embraced in man's world. Assuming that her Wonder Woman armour is from Themyscira, then I think that is more reflective of the relatively practical, functional, basic and muted fashions which would be worn by the Amazons.
3. I'd like the red, blue and gold colours to come from the Amazon flag or to somehow relate to the Amazon culture and civilisation. At the same time, I could see the brighter, primary colours being reserved for the "royal" family (although I don't see Hippolyta and Diana holding themselves "above" the other Amazons, especially to the extent that the Amazons are forbidden from wearing certain colours).
I'd prefer to see a wide range of personal styles amongst the Amazons, but I suspect we'll get costumes which are more uniform in style, with mostly dull brown/maroon/beige/navy colours being used.
