The phenomenon notoriously exists but it’s impossible to quantify because as a rule we can’t measure things that only exist in the past. Also, laypeople generally don’t understand the difference between “colorimetrically accurate” and “the version that best reminds me of the scene"
The closest thing would have been R.W.G. Hunt’s experiments with photos of female models who were known to the viewers. It was therefore possible to find out whether the fleshtone of the actual women matched the recollection of the viewers. They did not; Hunt found that a more suntanned appearance was considered preferable, possibly more accurate.
Chevreul, in his Chapter 5, says
It is almost always so that accurate, yet exaggerated coloring is found more pleasing than absolute fidelity to the scene, and one cannot deny that many people who enjoy savoring the exagger- ated modifications would not find the same pleasure in viewing the actual colors, because their sensitivi- ties require the changes introduced by the artist.
And in Chapter 16, I show how my own correction of another Niagara Falls photos closely resembles the treatment of two nineteenth-century painters, and none of the three of us are particularly near the actual colors in nature. Yet this is evidently what reminds the typical viewer of Niagara Falls.
We would never be able to get away with that kind of saturation boost in a fleshtone, which shows that the topic is not amenable to easy answers.