Good article but it has a problem with correlation and causation. Even though blacks were probably ignored the limitations of earlier color films were a big factor and beyond any mendacity. While the authors talk a lot about Shirley calibration cards, the calibration of the processing machines wasn't the issue. The biggest issue is merely hinted at. That is, to photograph dark skin, even with a poor film it is necessary to know what a light meter is and how to use it. That't why professional photographs made in this of dark skinned people are pretty good but the amateur ones are lousy. Time went by, the contrast range and color fidelity of film improved and the problem was solved. Kodak and or another maker could have tuned an early film for dark skin but it probably would have been derided as "nigger" film. Bummer.