I don't know a lot about The Batman (2022) or its relevant media, but I saw @gl1tchr's post, and it got me thinking about a little maybe-idea that I said before, but I think I'll elaborate on a bit better here.
Namely colour symbolism with Paul Dano's Riddler - as it currently stands, this Riddler is only one kind of green all over, almost this more grey-hinted, olive colour, and gl1tchr wondered in the post whether or not Riddler would gain any purple to his colouring in the next film.
So I thought about this, because if he changes his outfit, it would probably be deliberate for whatever reason. New change, perhaps, but adding a whole new colour too seems like it could be a good opportunity for some motifs! As such, the addition of purple specifically was interesting because yes that is the other colour associated with the Riddler, but who else can purple be associated with? The Joker.
We saw that whole "friend" riddle when (who I presume is) Joker is trying to get through to Edward, which he seemingly does, given his reaction, so what if the addition of purple to the Riddler costume ends up being representative of Joker's influence, steering him further from what he thought he was and more into what we know the Riddler as, more classically? Almost like how Joker does with Harley in other versions, except tweaked for this, of course.
The purple could be his newfound flamboyancy, his different confidence, his new muse. If the Batman doesn't want him, perhaps this new person does - he even stoops to converse with him in riddle, after all! What more could Edward possibly want?
Joker is probably going to steer him down a much worse path but it would be interesting to see Edward get more and more "Riddler-like" as it were (in terms of what's generally associated with him, as we can all agree Naston is rather different from what is usually presented of him at surface value) as a result, which would probably drift him further away from Batman.
In which case, perhaps the green will lose its murk, too, and it'll become brighter, more reminiscent of the character's costumes from other versions, essentially losing the "darkness" factor (black or grey or however you want to look at it), because in this scenario, the "darkness" is representative of Batman, or his belief/trust in him (also works since those are Batman's main colours). His outfit growing more saturated and brighter would essentially be his realising that he liked the version of Batman he had created in his head rather than the one that actually prowls Gotham at night.
I assume Joker is going to manipulate/leave him? So that will probably have some effect too, perhaps the change/addition of multiple question marks which partly may be his "confusion" at the way people keep doing this to him, not knowing who to trust, that he's an enigma, etc. (this may also be when he finally changes his name to Edward Nigma - Nygma? - because he's finally found his identity), but also his finally solidifying who the Riddler is and that he's his own person and no longer needs to work alongside someone, giving him that independence, for better or for worse. He's intelligent, tricky, and having finally figured out he can rely on himself and no-one else, he's more dangerous a force than ever. He is the Riddler, and he finally knows what that means.
Again, I'm no expert on the 2022 film, so I could be off the mark entirely, but it was just an idea I thought I'd elaborate on.
