Firstmost and as clearly as I can: I'm just brainstorming. I have a certain commitment to color-first games, but none at all to a color-first design process. "Wrong design" my butt, one way or the other.
Given that, here's a thing you can consider, Ry. Take one of those arbitrarily, let's say the 60's. One possible payoff embedded in the 60's is a struggle between generations, sure. But it's not the only payoff embedded in the 60's. There's exciting idealism vs practicality vs cynicism stuff too, which needn't break out on generational lines at all. Gender stuff, race stuff, sex stuff, causes and violence and interpersonal drama of all kinds. Art vs advertising vs kitsch (which don't, despite the casual glance, line up with idealism vs practicality vs cynicism). The range of payoffs embedded in the 60's is pretty wide, and it's a different range from the equally wide ranges of payoffs embedded in Greek mythology, dystopias, and elves.
Can you design a game that takes the 60's as established and then drives play toward one of the 60's' embedded payoffs, without choosing which payoff upfront? That's how Apocalypse World works.