"Non Metallic" Metallic or NMM for short is a method of painting metallic without using metallic paint. This technique is no different than regular highlighting/shading with blending, layering or feathering method. The most important thing to make NMM look 'believable' and 'real' is the consistency of "light source". I will share more info on this technique later, meanwhile, I wrote this color list that I regularly use for my NMM. I hope you can find it useful :)

Steel 1
GW Chaos Black, Black + Codex Grey (50-50), GW Codex Grey, GW Ghostly Grey, GW Skull White

Click on thumbnails below to view samples:
   

Steel 2
GW Chaos Black, Black + Shadow Grey (50-50), GW Shadow Grey, GW Space Wolf Grey, GW Skull White

Click on thumbnails below to view samples:
 

Gold (Warm color)
GW Scorched Brown, GW Bestial Brown, GW Snakebite Leather, GW Bubonic Brown, GW Bleached Bone

Click on thumbnails below to view samples:
   

Gold Nugget (Green gold)
GW Scorched Brown, Vallejo English Uniform, GW Snakebite Leather, Vallejo Green Ochre, GW Bleached Bone

Samples: coming soon.