I will present novel tests of galaxy formation theories using the large-scale structure measurements from the Sloan Digital Sky Survey (SDSS). I will first introduce the iHOD model, a probabilistic framework for mapping galaxy properties to their underlying dark matter halos. By modeling the color dependence of galaxy clustering and weak gravitational lensing, iHOD reveals a surprisingly simple picture for "galaxy quenching", i.e., the cessation of star-formation activities within galaxies. In particular, the probability of a galaxy being quenched is strongly tied to the mass of its host halo, regardless of the stellar mass or halo formation time. This simple halo quenching model can also successfully explain the environmental dependence of colors, as measured by the mark correlations of colors, as well as the curious effect of color conformity.
