The performance of colorless wavelength-division multiplexing passive optical network (WDM-PON) systems suffers from transmission impairments due to Rayleigh backscattering (RB). A single feeder fiber colorless WDM-PON architecture was modeled, simulated and analyzed at 25 km distance that sustained the noise induced by RB. We analytically compared the performances between single feeder and dual feeder WDM-PON architectures based on array waveguide gratings (AWGs). For single feeder WDM-PON, the high extinction ratios in both return-to-zeros (RZ)-shaped differential phase shift keying (DPSK) downstream and intensity remodulated upstream data signals helped to increase the tolerance to the noise induced by RB. However, a cost effective colorless system in dual feeder WDM-PON architecture was achieved without any optical amplification and dispersion compensation, low power penalty. These results illustrate that single feeder fiber architecture was cost effective in terms of deployment having a power penalty, while dual feeder fiber had lower power penalty thereby with better performance. Simulation results show that downstream and upstream signals achieved error-free performance at 10-Gbps with negligible penalty and enhanced tolerance to the noise induced by RB over 25 km single mode fiber.