This is my take on Trovarion's Grimdark grey Necrons

Grey Armour

1. Start with a Black
2. Mix Green Brown with German Fieldgrey WWII and pattern over the black base. Build this up in strokes allowing the dark to show through in places. Leaving dark near the edges seems to work.
3. Layer the above mix in with Rakarth Flesh
4. Then layer some Wolf Grey into with pure Wolf Grey being the highest highlight.
5. Add scratches with Rhinox Hide
6. Spot wash the shadows with a mix of Skrag Brown mixed with Sepia Wash

Green Glow

1. Use Warp Lightning to add a base tint.
2. Flat Green is the dark base, moving to Moot Green moving up with Golden Olive and Middle Stone

Silver Metals

1. Over a black undercoat, start with Gunmetal Grey
2. Wash the metal with Black Templar
3. Wash with a diluted Skrag Brown to give a rust efect.
4. Highlight up with Silver