Had to google what gilded blue might be. Suprisingly, I got some Ultramarines pictures, and they compare quite well to real armour pictures. So maybe seek an Ultramarines painting tutorial?
Otherways I would think non-metallic-metal. Or you might test blue shades on silver. A frien did something like that a couple of years back and got good results. But he tried different recipes for a good while.
-Zyg