"Well, the rainbow has a lot of colors," Saldana said in an interview at Comic-Con, laughing. "I dig it. I like being in space. I get to play less girlfriends, more female parts, more women. So I find it meaty."
The actress portrays green-skinned alien Gamora in Marvel's "Guardians of the Galaxy" after going blue in James Cameron's "Avatar," a role she's expected to return to for sequels. And she recently reprised her other space-bound character, Uhura, in JJ Abrams' "Star Trek Into Darkness."
"It's a testament to how creative the people that conceive supernatural and science-fiction kind of stories," Saldana, 35, said of her love for the genre. "They're able to build something out of nothing by just imagining it. I have a huge fascination with that. Filmmakers like JJ, like ("Guardians" director) James (Gunn), like James Cameron. ... You need to be really, really special to do that. So I like being with special people."
Chris Pratt is among Saldana's co-stars in "Guardians," which had been filming for just a few weeks in the U.K. before its actors dropped in to show fans footage at Comic-Con.
Pratt plays Peter Quill, an interplanetary gunslinger known as Star-Lord who assembles a team of aliens to do battle. His character's wit and rebellious spirit has been compared to another planet-hopper, Han Solo.
"You can make the comparison, that's for sure," Pratt said, acknowledging that like "Star Wars," `'Guardians" - set for release next summer - is "a big space opera."
Saldana was more emphatic: "It's an awesome comparison. Are you kidding me? Harrison Ford!"
But Pratt, 34, said he has more pressing concerns as he returns to set.
"I just feel like, I'm hoping every day that they're not going to fire me," he said. "I'm like, `So you saw dailies yesterday and I still have my job?' They say `Yeah!' So for now I do."
Follow AP Entertainment Writer Ryan Pearson at http://www.twitter.com/ryanwrd .