In the digital age its fun to experiment. Many seem to enjoy the possibilities of variations. Obviously, some don't. Its a matter of personal taste. I've done quite a lot of color to B&W and sepia conversions but, mostly on request by those wanting to see the possibilities. I can understand where an artist may see their works distorted without their permission and take offense. I've also seen them take it as a compliment. They were pleased to see their works were interesting enough to experiment with by someone else, provided they were done skillfully. Selected color works can be interesting to some also (a mixture of B&W).
All these experiments/enhancements/conversions fuel imagination and explore possibilities, although, I do understand how some may place a greater value on a subjects original form.
Maybe a bit off topic but, this is one example of something I find fascinating. From a simple nude form to a piece of art (IMO). All effects added by the original artists. Possibly hideous or unnecessary to others but, quite intriguing to this viewer in its addition of textures along with colorization.