Put "ancient Egyptian people" into a Google image search, and none of the resulting photos resemble Christian Bale or Joel Edgerton, stars of Ridley Scott's biblical epic "Exodus: Gods and Kings."

The director inflamed calls for a boycott of the film with his recent comments that he couldn't have made such a big-budget movie if "my lead actor is Mohammad so-and-so from such-and-such."

"I'm just not going to get it financed," he told the trade paper Variety. "So the question doesn't even come up."

The question, perhaps, being: Should Hollywood be concerned about casting white actors to portray people who were definitely not white?

It's an institutional problem, said professor Todd Boyd, chair for the Study of Race and Popular Culture at the University of Southern California. Hollywood is a place where profit is king, he said, and it rarely takes big-budget risks on casts of color.

"The way movies get financed, and the overall ignorance in this country about Africa, explains why you'd have a big budget film with a very well-known director backed by a well-known studio mogul and get this problematic representation in 2014," he said.

The financial argument doesn't hold up. What might make a movie successful is speculative, and those with diverse casts are just as likely to become global box-office hits. Consider the "Hunger Games" and "Fast & Furious" franchises. The latter has made more than $2 billion worldwide.

"Exodus" stars Bale as Moses and Edgerton as Ramses. Actors of color occupy minor, mostly non-speaking roles.

There's a long history of such casting in Hollywood. Moses - who the Bible and historians would say came from the north African nation of Egypt - was only brown-skinned on the big screen as an animated character in 1998's "The Prince of Egypt." Otherwise, Hollywood's version of has been white, played by actors such as Charlton Heston and Christian Slater.

Rupert Murdoch, who owns the studio that produced "Exodus," defended its casting on Twitter. He wrote, "Since when are Egyptians not white?"

He followed up with, "Of course Egyptians are Middle Eastern, but far from black. They treated blacks as slaves."

Representatives from 20th Century Fox declined comment and Scott was not available for an interview for this story.

Another biblical epic, "Noah," also faced criticism for its all-white cast led by Russell Crowe. At the time of its release earlier this year, screenwriter Ari Handel said the filmmakers opted for an Anglo cast so as to avoid calling attention to issues of race.

"They're supposed to be stand-ins for all people," he said. "Either you end up with a Bennetton ad or the crew of the Starship Enterprise."

It's not unusual for some ethnicities to play others on screen. Mexican actor Gael Garcia Bernal portrays an Iranian journalist in "Rosewater" and Japanese actor Ken Watanabe played an Arabic villain in "Batman Begins." Yet Boyd notes that actors of color are rarely, if ever, cast as white figures. For example, he said, Hollywood wouldn't make a movie about Princess Diana with Kerry Washington in the lead role.

"That's basically the equivalent of what's going on, but in reverse," he said. "They would never neglect to cast a white actor as a (white) historical figure just because there were box office concerns."

While Will Smith and Denzel Washington are as bankable as Brad Pitt or Tom Cruise, Hollywood has been historically reluctant to cast minority stars in tentpole leading roles. While "Hercules," starring Dwayne Johnson, failed to recoup its budget this year, Washington's "The Equalizer" was a $190 million international hit. Kevin Hart has also proven to be box-office gold, with "Ride Along" and "Think Like A Man Too."

A recent USC study of race and ethnicity in film found that while non-Caucasians make up 44 percent of moviegoers, they're represented less than half that much on screen. Among the 100 top-grossing films of 2012, almost 11 percent of speaking characters were black, five percent were Asian and just over four percent were Hispanic.

Actor-producer Harry Lennix, who appeared in "Man of Steel" and stars on NBC's "The Blacklist," has started making his own movies - including one that features a black Jesus - and advocates for artists to create and fans to support the kind of movies they'd like to see, where quality transcends color.