From Sara Lance's death to the dismantling of Oliver Queen's personal life, "Arrow" season three took on a dark tone in order to service its dark storylines. However, according to executive producer Marc Guggenheim, that's about to change.

In an interview with io9, Guggenheim revealed,

[The show] will take a lighter tone. That's pretty much the only thing I say without spoiling it. We've been working for about a month now in the writers' room, talking about season 4, and I think that one thing we all collectively understood was season 3 beginning with Sara's death, because it's the death of a major character on the show, it set a tone for the remainder of the season. And I'm not the least bit apologetic for that tone. I happen to like dark and I like the fact that Arrow is a pretty dark show particularly for a network show. That said, every year you want to mix things up and there was sort of a collective desire on all of our parts to try to inject a little bit more lightness into the show, a little bit more humor. It's not going to radically change. The show's still going to be the show but in terms of tone we're coming off a very very hard season for all of our characters. We wanted to try to mix it up a little bit.

He also touched on the way Oliver's character has developed over the course of the show, saying, "[Oliver] is in constant evolution and part of being in constant evolution and needing to grow both as a hero and as a human being is the fact that he doesn't always make the right choices. Or at the very least he makes choices that feel right to him but don't feel right to other people. And I think that's something we definitely see in play in the final episode of season 3 whereas Bruce Wayne, y'know, he usually gets it right. To me that's the key difference."

On the subject of "The Flash"/"Arrow" spinoff, "Legends of Tomorrow," he added, "It's definitely not just the team show. I think the show is going to be bigger, louder, more ambitious even than 'Flash' and 'Arrow.' I think 'Flash' raised the bar on 'Arrow' in terms of adding superheroes and we're looking to now have the show raise the bar on 'Flash' so you feel like the shows are getting bigger and bigger. One thing we sort of always tell you is that with 'Flash' we're really trying to provide a feature film every week. With this show we're trying to provide a summer blockbuster every week."

"Arrow" returns to The CW this fall.