We demonstrate color-free operation of a dense wavelength-division-multiplexing passive optical network based on the wavelength-locked Fabry-Perot laser diodes with injection of a low-noise broadband light source (BLS). The color-free operation, i.e., wavelength-independent operation, was obtained at 50-GHz channel spacing with the help of a narrow injection bandwidth of the low-noise BLS. We also demonstrate three-channel upstream transmission with 100-Mb/s Manchester coded data.