Zoe Saldana has enjoyed a successful career for decades now. But fans think they've identified a problem in Hollywood, and Zoe's career is a solid example of what they say is a widespread issue.

It's not just Zoe, though; fans say actresses like Jennifer Lopez and Mindy Khaling are additional examples of an on-screen trend that they really don't like.

Fans Point Out This Problem With Zoe Saldana's Films

Though not every project Saldana has been involved in is a good example, fans say they've identified a problem with many films that she's been in. And it's not that she's being underpaid; that's a separate issue.

On Quora, fans discussed what they perceive as a serious problem with diversity in Hollywood. They claim that many actresses of color are mostly cast alongside romantic interests that are white.

In contrast, fans elaborate, white women aren't often portrayed with love interests of any other culture, ethnicity, or race. And when they are, that premise is basically the entire plot of the film or show.

Fans Say Hollywood Casts Zoe With Specific Co-Stars

Commenters noted that Zoe Saldana's film resume is a key example of the trend where women of color wind up with white guys. Though not all of her films follow the pattern, it's interesting that a remarkable number do.

And some of the examples are pretty clear; in 'Guess Who,' she wound up with Ashton Kutcher's character, and the entire plot of the movie had to do with Saldana's on-screen dad not approving of the relationship.

RELATED: The Truth About Dave Bautista And Zoe Saldana's Relationship

Even in 'Avatar,' Zoe's character winds up with someone who's not only a white guy, but a white guy who transforms into an avatar of Zoe's character's culture in order to (among other things) win her over.

It's interesting to look at Zoe Saldana's resume with this trend in mind. But it's just the tip of the iceberg when it comes to Hollywood's issues with casting and race.

Zoe Saldana Also Plays... Different... Women Of Color

Fans definitely give 'Avatar' a pass (everyone's an alien, right?), but there are other films of Zoe's that are problematic for other reasons. For one thing, the black Dominican actress (both her parents have Dominican ancestry) often portrays women of different cultures and heritages.

While Quora fans didn't dive into that particular topic, it's an offshoot of the issue they did bring up, and something that many fans wish Hollywood would more openly address. After all, it can't be that impossible to find a Bolivian actress to portray a Bolivian woman, or a Colombian woman to play a Colombian woman.

Either way, fans sure hope that bringing up these issues will spotlight continued challenges with representation in Hollywood -- even though they love Zoe and her acting abilities (including the fact that she does many of her own stunts).

NEXT: 10 Posts On Zoe Saldana’s Instagram That Will Make You Love Her Even More