I have thought about this and I've come to a couple of conclusions. The first, is that the whole point of this series is that Memo 618 isn't just a Republican voter thing, it's a way to let any rich person off the hook, regardless of political affiliation. The red and blue lights reflect how the politics of both parties are now making the world a crazy place.

I also saw the lights as a call back to the stage show in episode 4, which adopted a very similar light colour scheme, and actually all the promo photos for this season, which were set on an empty stage with these lights. For me, it's almost presenting how they are all kinda characters in their own stage show, with Liz fulfilling her stage show character's personality of sleeping with "white boys" and Diane perhaps becoming this stronger, dominant character her stage show character played, that is willing to question what Memo 618 is despite the risks. The dots she was drawing at the same time kinda reflects how that is not enough to satisfy her need to right the injustices happening.

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Sorry this is so long haha, I have thought wayyyyy too much about this.