A colorless wavelength-division-multiplexed passive optical network with broadcast capability is proposed and experimentally demonstrated. The polarization-multiplexed downlink unicast and broadcast signals are injected into a polarization-sensitive weak-resonant-cavity Fabry-Perot laser diode for uplink remodulation without polarization control. Transmission performances of downlink unicast and broadcast as well as uplink signals are investigated. Detailed analyses of injection polarization dependence, injection-locking range, and power budget are provided.