Regarding the “white heroes”, at the time I don’t think the audiences would be drawn in by non white heroes.
Today? No problem with men and women of color. The number of headlining African American actors and actresses would be widely accepted: Jamie Foxx, Denzel, and Samuel l Jackson come to mind.
We HAVE grown in our acceptance of a good story and good filmmaking. Think of the biggest summer hits in the past ten or twenty years. Lots of actors of color carrying movies.
Let’s not fall for the Left’s race lies, particularly about America. There have been any number of very successful black entertainers throughout American history. For myself, I don’t care about the race of the actor, but the quality of the story, acting and film work/editing.
For instance, here in Chicago it is common for directors or producers to cast blacks in the lead roles for Shakespeare. I judge them just like any other Shakespearian actor, most of whom don’t get it right.