A reflector lamp has a generally parabolic shaped housing (12) with an interior surface coated with a layer (14) of silver having a protective layer (16) of a stable protective material, such as silica, disposed thereon. The thickness of the protective layer is selected such that at least one of the following relationships is satisfied: a color correction temperature of the lamp is no less than about 60 K below that of the light source, and a % reflectance of the reflective interior surface is no less than about 3% below that of an equivalent reflective interior surface without the protective layer.