Earlier prototype electronic inks could display just two color values (usually black and white); however, photonic ink can display any color value in the spectrum.

Among other applications, photonic ink can be used for refreshable, full-color images in an electronic newspaper, to coordinate pictures with updated newspaper content; as well as, in electronic books.

Photonic ink displays color through a controlled diffraction, a special type of interference which is responsible for the iridescent color effects of opals and butterfly wings.