Open a photo and grab a darker pixel’s color with the eyedropper. Paste it on the same pixel with the pencil tool. Try until you clearly see that many colors are re-applied completely false!
I tried it on several completely different pictures. Always the same result.
Even a difference of one single step of the 257 RGB-steps in just one of the three RGB-colors - which would be invisible by far for the human eye - would make every picture editor a joke.
Vista and earlier, Paint always worked absolutely correct.
It’s so unneeded and poor.