Rather than blame the tools for inadequate results it would be better to blame the lazy workmen (and women) that misused them!
It was perfectly possible to expose colour film to render beautiful results showing a black person's skin in the same frame as a perfectly rendered version of a white person's skin well before the dates she claimed for the "brown furniture" changes.
Consider In the Heat of the Night from 1967
The film makers used the tools properly and we enjoyed the results.
Just because so many (including herself by her own account) failed to achieve similar results is not the fault of the film stock or the lighting equipment or the cameras. It was their fault that they didn't use these correctly. A lack of skill is the culprit not a lack of consideration.