The problems being discussed are more than just the ability of film at the time to capture things , it's the education around it. Shirley cards and books around that time were built to normalize white skin and blonde hair. It wasn't even considered a problem at the time that black skin wasn't reproduced well until furniture and chocolate manufacturers complained that their products weren't well shot.

There's both a technical and a societal element to it.

I suggest watching this video , especially from the 25 minute mark

https://youtu.be/ROuE8xYLpX8