Different formulations of copolymers can be used to adjust or "tune" the energy levels (HOMO and LUMO) and the color of light emitted by an organic electronic device. The copolymer may principally include of electron-rich and electron-deficient monomeric units whose composition and number are chose to optimize the efficiency of the device. A relatively smaller amount of fluorophore monomeric units may also be used to adjust the emission wavelength. The copolymer can be used in displays and potentially other electronic devices.