We demonstrate ultralow dark currents in blue- and green-light-sensitive organic photoconductive films (OPFs) with transparent top electrodes. Using a reactive ion plating process, we investigated the cause of damage during InSnO (ITO) deposition on the OPFs, and we demonstrated the minimization of the damage as well as the optimization of the materials and structures of the OPFs. We found that dark current densities as low as several 10 pA/cm² can be achieved with both OPFs using ITO top electrodes with a visible transmittance of ~90%.