Two donor-acceptor systems, 4,7-di-2-thienyl-2,1,3-benzoselenadiazole (TSeT) and 4,7-di-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl-2,1,3-benzoselenadiazole (ESeE) are synthesized and electropolymerized to give polymers PTSeT and PESeE, respectively. One of the polymers, PTSeT, is blue-green in the neutral state and soluble, exhibiting a deep-red emission color. The other, PESeE, is the first 2,1,3-benzoselenadiazole-based neutral state green polymer with a narrow bandgap (1.04 eV). Furthermore, PESeE has superior and durable n- and p-doping processes. Beyond the stability and the robustness, both of the polymer films exhibit multi-electrochromic behavior.