Conventional image sensors achieve color imaging using absorptive organic dye filters. These face considerable challenges however in the trend toward ever higher pixel densities and advanced imaging such as multispectral imaging and polarization-resolved imaging. In this talk, we will present a new paradigm for color imaging based on all-silicon nanowire devices without any color filters. We fabricate pixels consisting of vertical silicon nanowires with integrated photodetectors, demonstrate that t heir spectral sensitivities are governed by nanowire radius, and perform color imaging. We also demonstrate polarization-resolving photodetectors consisting of silicon nanowires with elliptical cross sections. Our approach is conceptually different from filter-based methods, as absorbed light is converted to photocurrent, ultimately presenting the opportunity for very high photon efficiency. This work was performed at Harvard University under the supervision of Prof. Kenneth B. Crozier.