We have designed and synthesized a large number of donor-acceptor type organic electrochromic (EC) materials to increase the resistance to ultraviolet irradiation. The guiding principle for the molecular design is given briefly. One of the materials is a viologen-ferrocene EC material. In this paper, we report two different types of electrochromic windows (ECWs): one is fabricated with a viologen-ferrocene EC material, and the other with a carbon-based electrode. The coloration process of the viologen-based ECW is also discussed with reference to the driving voltage dependence. Outdoor weathering tests were carried out on ECWs designed for automotive applications. The 2-year outdoor weathering tests suggest a potentially high durability. (C) 2003 Elsevier B.V All rights reserved.