I don't really see how throwing blood and gore at something makes it dark (if anything they made Origins look childish). The darkness of a setting comes not from the number of gallons of blood you see on screen, nor even the colour pallette used, it comes from the characters, and the stories, it comes from the way people and things act and react. You can easily have very dark settings where everything looks bright and cheerful. The heart of darkness is candy coated (imaginary cookie for those that get the reference).
Overall, I'd say Thedas is a pretty dark setting. The world is not a nice place to live in. We see opression and prejudice. We see war and it's brutality. We see a world on the brink of destruction.
But yet, despite that, I consider Origins to not actually be that dark. Why? The story. Ultimately, depsite the darkness of the world it takes place in, the main plot of DA:O is remarkably optimistic. Yes, bad things can and do happenover the course of the game, but in the end, our intrepid hero can unite the people of Ferelden and lead his merry band to save the day from the forces of darkness. Throw in the ritual and this can happen pretty much without cost. There's no negative consequences to your actions. There's no sacrifices. Sure, you can play in a way that involves taking darker decisions, but in a truly dark story, you would have to do so - or at least, if you didn't, there would be major consequences. DA:O's story is a heroic fairytale, that happens to be set in a crapsack world. Of course, that isn't neccesarily a bad thing, as indeed, it's a well told and enjoyable story. There's a place for idealism, for escapism. Not everything has to be grimdark. And in many ways, putting such an optimistic story in such a harsh world makes its message even greater - that even among such horrors, there is light.
DA2, by comparison, IMO, is a much darker story (and before someone jumps in here, I'm simply talking about the underlying plot and not taking notice of any flaws in its implemetation). In the end, Hawke can't save the day, Kirkwall will collapse into conflict no matter what he does. There's no idealistic happy endings, there's no triumph of heroism over darkness. Sometimes all you can do is give your best, only to find that your best simply isn't good enough to save everyone. You can help, you can make things less bad than they might have been, but in the end, you're just a man, and there's a limit on what one man can do. It's a much darker, more realistic outcome than Origins.
So much THIS!
Yes, DAO was dark. It looked dark through the art style and it dealt with some serious twisted stuff. But I agree that it was far more optimistic and heroic than DA2. And I got the feeling that many people did not appreciate a game where the hero FAILS in the end. I know that the majority of complaints were directed at the map recycling and streamlining. And rightly so. But many strongly disliked the story too. Because you have no control over your companions' actions in the end. That was the impression I had anyway.
I never understood what's bad about having a hero watching helplessly as everything goes to ****. It felt refreshing to me. In DAO you knew from the beginning that you would defeat the archdemon. It comes at a sacrifice. But from the start you know that you're screwed as a warden. Your job is a suicide mission. That *is* dark.
But not as dark as the mage rebellion that started in DA2 and is in full bloom now.
I thought Hawks would restore order somehow. Nope! You see the tragedy with Anders coming but you can't talk him down. That's really gloomy stuff. How the world looks can add to it but it would be just as gloomy if the church got blown up in a daisy field.
I've always loved the mage/templar conflict for it's complexity and reflection of reality. DAI actually feels almost uncomfortably close to real life these days with the way everything is becoming radicalized. All this terrorism as a response to oppression. Thedas is playing this out as a fictional scenario. And just like real life it's shades of gray. And very depressing.
Emotionally I was felt more removed from DAO's story. It felt very much like video game fantasy. There are no archdemons in real life. I felt for the characters but Darkborn storyline was meh. All this racism and fear in Thedas however feels very real.
So yeah, DAI LOOKS more colorful. No rape scenes. It's not about the oppression of women this time. Not so much about the elves either. That got dealt with.
The focus is full force on this civil war. And it's an incredibly ugly thing. It's depressing to see so much resentment and fear directed at pretty much everyone. It's far darker to see people kill each other over religion and superstition than seeing people get slaughtered by orcs. To me anyway. Because it's what's happening every day in real life. Adding tons of rape scenarios and women being beaten to death might have been a bit too much. DAI is plenty dark to me...