@The_Minks, here is a link to a video tutorial I used when deciding what kind of blue I wanted. I used the exact same colours, which are excellent with an airbrush (50/50 dilution with Ammo Mig acrylic thinner).
https://www.youtube.com/watch?v=l1_0ye2TMRU&list=PLwFoj7hjq6jkdkQsZ8G0jTJv1eOaKRuyw
@Subtleknife : Quite simple actually ... over a black undercoat:
- GW Retributor Armour
- GW Reikland Fleshshade wash (pure)
- GW Liberator Gold (slightly diluted)
- GW Liberator Gold/Silver (I used Ammo Mig silver but any silver will do, again slightly diluted and only where light would hit most from a zenithal point of view)
- Ammo Mig silver on the edges (again, any silver will do)