Abstract: Display devices incorporating an improved working electrode are disclosed. The devices comprise a transparent outer layer, a first electrode having a reflective surface facing the transparent layer, an electrochromic material located between the reflective surface and the outer transparent layer, an electrolyte in contact with the electrochromic material and a second electrode located behind the first electrode. The first electrode is ion-permeable, allowing ions to pass through and contact the electrochromic material in order to alter the optical properties of the material. The electrochromic material is preferably a conductive polymer such, as polyaniline. The display devices are capable of changing reflectance and/or color by the application of an electric potential to the electrodes.