A copolymer of 2,2':5',2 ''-terthiophene and 3,4-ethylenedioxypyrrole was synthesized as a new electrochromic polymer and its spectroelectrochemical properties were investigated. This copolymer shows multicolor electrochromism, switching between dark blue, light brown, and orange-red. Three different electrochromic materials were evaluated using the electrochromic copolymer. Double potential step chronoamperometry experiments showed that this copolymer film has good stability, fast switching time and high optical contrast. (C) 2009 Elsevier B.V. All rights reserved.