Polarization of the light scattered by the lunar surface contains information on the mean particle size of the lunar regolith, which gradually decreases by continued micro-meteoroid impact over a long period and thus is an age indicator of the surface. We performed multi-band (U, B, V, R and I) polarimetric observations toward the whole near side of the Moon at the Lick observatory using a 15-cm reflecting telescope with 1.1km/pixel spatial resolution at the center of the lunar disk. We analyze the color dependence of the polarization properties of the lunar regolith and discuss its implication for the study of lunar swirls.