I did say that Smallville had dark aspects to it. That being said, Smallville was certainly brighter than Arrow Seasons 1 & 2, even at the darkest moments throughout its run. And perhaps its all relative though I would argue that early on in Smallville's run there was brightness, in the lighting, in the costuming, Kent family values, etc., and also darkness with the Luthors and the meteor freaks, the ambiguous mission set forth by Jor-El, and also the angst. But there was also the callbacks to the bright and hopeful Donner universe.
Honestly, I don't think it's very useful to try to simplify everything into a binary "light vs. dark" model. Reality isn't defined by opposing extremes, it's mostly about all the stuff in between them.
I agree with you that Smallville came out before superheroes were cool in the mainstream. I hadn't thought about the inclusion of more comic book stuff on the show being tied to the success of Iron Man. That's interesting. I just thought it was the creators moving on in the process of getting Clark to Superman.
Well, the creators -- Alfred Gough and Miles Millar -- had no desire to get Clark to become Superman. They spent seven years having Clark resist his heroic destiny and cling to the life goal of being an obscure, unassuming farmboy, dragging it out to the point that it became impossible to believe their version of Clark Kent had it in him to
ever become Superman. It wasn't until they left the show after season 7 that their successors
finally, finally broke Clark out of that rut and started to make
Smallville into a Superman show in all but name.
So the change in showrunners was part of it; the change in the culture as superhero movies became a hit was another part. The third part was that the show ran twice as long as its creators ever expected, so they exhausted the potential of the "farmboy with paranormal abilities" premise and had little choice but to mine the comics storylines for material. To the point where, quite ridiculously, they'd had Clark form the Justice League, defeat Luthor, and battle Doomsday, Zod, and Darkseid before ever actually donning a cape and calling himself Superman. Even when the show finally tried to become a Superman show, it was hampered by the original mission statement to focus on Clark's pre-Superman life. A lot of fans, critics, and observers argued for years that they should change the title to
Metropolis, or just end the show and relaunch it as a straight-up
Superman series, but it just clung fanatically to "no flights, no tights" years longer than it made any sense to do so. Which was one of the things that kept it from really working as well as it could have.
Though when I think about it, arguably Smallville Season 6 (2006) is when the show really got more into the comic book stuff, with the introduction of Green Arrow and that predated Iron Man (2008). Also, in the first five seasons they had threaded comic book heroes throughout the show (Cyborg, Impulse, Aquaman) so that's what made Season 6's "Justice" so very cool, to see them all team up.
Well, sure, the cultural shift wasn't about a single movie.
Iron Man is a convenient demarcation point between eras, but the transition took a few years surrounding it. And yes,
Smallville did tentatively work in other superheroes, but it put them in colorful hoodies rather than going for all-out superhero costumes. They were still embarrassed enough about the comic-book stuff to try to substitute a more "grounded" look. But a few years later they were doing things like Michael Shanks's really cheesy but comics-accurate Hawkman costume.
I don't think the Berlanti's shows are that much brighter (Arrow excepted) than what DC has put out before. I mean we're looking at Wonder Woman, Lois & Clark, Flash (90s), The Adventures of Superboy.
Well, those are from an earlier era. Heck,
Wonder Woman came along less than a decade after the Adam West
Batman and was developed for television by one of its main writers. The era of "dark" comics pretty much began in the mid-'80s with
The Dark Knight Returns and
Watchmen, and it came to movies with the Burton Batman to an extent (though the Schumacher Batman films were pure camp). The superhero shows of the '80s and early '90s were still the inheritors of things like the Reeve Superman films -- though some "darker" tones were starting to manifest, there was still a lot of expectation that superhero fare should be fairly comedic or kid-friendly or campy. The modern era of superhero fare being taken seriously pretty much began with Bryan Singer's
X-Men, though along with that came a sense that superhero stories should be grounded and downplay the costumes and nicknames and such. But as time went on and superhero stories became more mainstream and acceptable, it became less necessary for them to shy away from the more comic-booky aspects, and now we're at the point where they can just pile on the colorful costumes and nicknames and wild powers and wilder storylines and be unselfconscious about it.
Arrow is that whole process in a nutshell. It started out trying to be very grounded and Nolan-Batman-like, as an "entry-level" show for audiences who weren't immersed in comics lore and culture -- but the cultural climate is different now than it was when
Smallville began, so
Arrow was able to do in just a couple of seasons what
Smallville needed to ease into over a decade, and now we have a totally uninhibited DC multiverse with Lazarus pits and magic totems and telepathic gorillas and alternate universes and everything else.
Granted, the 90s Flash was inspired by Burton's darker (for that time period) Batman film, but still I can't say it was that dark a show. It's about on the level of today's Flash, from what I can recall.
Ooh, talk about shows going through transitions.
Flash '90 started out trying to be dark and brooding like Burton
Batman -- not really a good fit for the concept -- and due to network pressure, it avoided using comic-book villains. But as the season went on, it both got lighter in tone and started using more supervillains, and by the season finale it was every bit as campy and goofy as
Batman '66. It went from one extreme to the other, and it was mainly in the middle of the season that it found the proper balance. The current show has been much better at maintaining a consistent tone and a good balance between the serious stuff and the fun stuff.