Why do colors fade?

Question

I'm not looking for what causes them to fade (sunlight, etc.) I want to know what the scientific explanation is.

Answer 1

The photons of the sunlight can be captured by the electrons of atoms and molecules potentially causing chemical changes. Different chemicals absorb different photons (based on their wavelengths) and faded colors present different mixtures of photons to your eyes. For example if all photons are reflected the color is white while if all photons except red are absorbed the color you see will be red. Bleach can also chemically change non-fast colors fading them. Dyes imparting color are chemicals that can be altered by exposure to photons.