There are two reasons. One Physics related and another Chemistry related.
1. Silver or other metal in general shine a lot. Generally when a surface is smooth and polished, the surface is more or less a planar surface. So when a beam of light falls on it, it is reflected in one direction. So most of the light is received by the eyes. We perceive that as a shining surface.
From a dull surface, very little light is reflected in one single direction. Due to roughness light is reflected in all directions. So light reflected in one direction is very small. They receives very less amount of light.
Even Silver, if not polished and when its surface is oxidized, it appears dull and not so shiny.
2. The metals in general contain conduction band electrons. They receive the energy in the received electromagnetic radiation, Then they get excited to next higher level orbital. They release the energy when they go to their orbitals. That released energy is reflected and causes the metal to be visible in one color.
Silver has electrons 4d that get excited to 5s. This energy gap is high and requires ultraviolet radiation. So Silver does not absorb visible light rays much and reflects most of that. So Silver shines very bright and White among all metals.
Gold for example, has conduction band electrons in 5d orbital that go to 6s. This gaps is less in energy. So visible light photons in the Blue color wavelength match that energy. Then Gold absorbs the blue color and reflects others. They mix and are visible as Yellow color.