colorizing seems like real creative work (if done by humans), and restoring can be too. Denoising, IMHO, not so much, and just cutting wouldn't be either.
Manual coloring is creative. "Restoring" is a bit of an ambiguous term, but generally, it would not be original expression either. Remember, the test for originality has nothing to do with effort. Restoring something to its original state is not new creative expression, but presenting the existing creative expression.
