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

i don’t believe there’s anyway to derive from grey what the original color was, because grey has no color attributes

But you can make some educated guesses.

Some colors are well known. Barns were red because the ingredients for red paint were easily available

Some colors were rare and expensive during certain times in history so they can be ruled out for all but the richest people

medieval paintings and tapestries show the colors worn by kings and peasants. the tiles and mosaics of pompeii.

museums contain clothing samples. also graves.