Abstract: The present invention concerns multilayer films comprising a plurality of layers, at least some of the layers comprise (i) cross-linked chitosan, alginate, chondroitin sulfate, or hyaluronic acid and (ii) particles or void spaces; wherein the layers are 20-260 nm in thickness. Also disclosed are multilayer films comprising at least two of: a layer comprising a first polymer; a layer comprising a second polymer; a layer comprising particles, wherein said particles comprise ceramic material, metallic species, or both; and, a layer comprising a combination of said first polymer and said particles; wherein said multilayer film is capable of displaying structural color. Also provided are methods for making and using the inventive multilayer films and compositions comprising the multilayer films.