Diversity

Go back in time to 1976 and start a protest!

Anyhow, for what it's worth, Box the Robot was voiced by a respected black actor, Roscoe Lee Brown, and I am sure a few of Ustinov's pet cats were black.

In 1976 America was 90% white. There was no need to pander to the diversity crowd.

Perhaps the races lived in separate domed cities or the war that ended the earlier civilization was a race war won by the whites or the computer(s) that managed society eventually became genocidal. The computers killed people once they turned thirty to manage the population, maybe their programming led to other perverse outcomes like only raising babies with certain characteristics.

The real explanation likely is that the crowd shots in the movie were apparently filmed in Dallas which had a population that appears to have been between 75-80% white in the 1970s.

For racism style future fun, check out THX-1138 where the whites are all slaves, and the blacks are only "entertainment" channels.

I'm sure today everyone reads all kinds of bad into that but I thought it was kind of clever, if you think about who is talented.

https://youtu.be/Rn-Sa0MlFkg?si=gtA-834098qezxQf&t=110