Type 4 was a material option, an Alpha Quadrant Alliance designation for the visual appearance of a spacecraft's outer hull, i.e. a vessel's "skin". This version of Type 4 was available for Ferengi starships and shuttlecraft. Type 4 covered the ship with a uniform gold- and latinum-coated alloy. The warp plasma in the nacelles and impulse engine appeared bright yellow.
Type 4 was the default material for the Nandi-class. (STO - The Iconian War mission: "Flying High")