Eli5: How do photo restoration artists know the supposed colors of greyscale images?

Question

Are the colors based purely on their assumptions/imagination, or do the greyscale images retain some sort of data that tells what color on what part?

In: 641

Answer 1

An interesting sidenote is that with planned black-and-white filming or photos, colors could be chosen exclusively for their black-and-white contrast. Accurately recreating a black-and-white movie’s original colors might produce a garish mess instead of what was originally intended.