Comment by monocasa

Because of the film technology at the time, a lot of the skin tones on set wouldn't match what you'd expect anyway due to makeup designed for the b&w film. Lots of sickly greens, yellows, and blues in place of red tones for instance.

https://www.bustle.com/articles/30501-i-tried-a-vintage-film...

At that point if you've already decided you want to colorize the film, there's a real question of how do you approach it, because being true to what was on set definitely isn't the right choice. So now you're playing with skin tones regardless.