Final Fantasy XV Director Hajime Tabata took to the official forums in order to explain the philosophy behind the theme of the game, while also mentioning a change made to the setting of the kingdom of Lucis due to rating reasons.

"Hello, this is Director Tabata.

Yes, this can be said added-afterwords because clothes Noctis and his companions wear was black to begin with. In the process of game creation, there are two patterns – one where there is a setting and game elements are determined based on that setting, and the other where we have game elements and a setting is created using these elements. So this case falls into the latter.

Those who already know a lot about FF15 like yourselves may feel these settings are unnecessary. But for those who have just been introduced to the world of FF15, these settings can be a great help in familiarizing themselves with this new world. Now let’s say you, do1pen, have been asked by someone, “What kind of a game is FF15?” It is hard to answer this question if you don’t have a clear idea what the most important theme is. The FF series comprise so many elements and it is among the most difficult games to explain in a few words. For FF15, we consider it very important to have a clear theme that you can explain in a few plain words. So my and all my fellow FFXV developers’ answer to the question “What kind of a game is FF15?” would be “a game to regain a kingdom once lost.”

By the way, in Versus 13 Lucis was set as a country of Reaper worship. This setting is a violation of the age rating criteria for games in some countries, so we cannot push these theme. To replace these theme, we have a backbone setting of “black as a special colour.” And I hope you will wait for more information to come on this."

One thing is for sure: Tabata-san is definitely more open than most about the development process and the decision making philosophy for Final Fantasy XV.

I don't know many developers that would explain this kind of details, and it feels pretty refreshing.