A number of images on wikimedia are associated with what was called the Google Art Project, what seems to have been a project to digitise paintings. Mind you, it’s not obvious from what I think is the associated site (Google Arts & Culture), which appears to carefully conceal any information behind the usual marketing–style content–defeating whizzo–junk.
I am going to presume that they hoovered the original images properly (they have the resources), so their images have a decent resolution (they all have done so far) which are straight (all good so far) and have the correct colours (there’s no way I can tell). I welcome their project and hope they continue it, I just wish they’re put an informative front end on it.