It is based w/ Vallejo Model Color Green Grey. (2 or 3 thin coats over white)
Then deepened with Reaper Grey liner (thinned with a controlled application).
Highlight 1 - Reaper Master - Cloudy Grey
Highlight 2 - Reaper - 1:1 Misty Grey/Cloudy Grey (on larger pieces of metal)
Highlight 3 - Reaper Master - Misty grey (highlight 2 on chains)
Highlight 4 - White.
Thinned Glaze of VMC Green Grey
Deepen with a mix of Green grey/Grey liner in spots
Final highlight of whit reapplied.
Rust color is thinned Parasite brown (Vallejo Game Color) applied in layers to build up.