This is the new enhanced spartan battle armor made specifically to fight covenant. The Silver parts are the enhancements. They are reinforced titanium with crystals in them to help diffuse the energy from covenant weapons. It has a kind of chrome on it that conducts energy across the whole piece of armor. The only disadvantage is its cost and weight. That is why there are only gauntlets and thigh plates. This is totally made up, so don't take this to seriously. :)