My ranging scale of silver used across my Necron army.

Dirty Silver

For your Necron Warriors, unkept Canoptek constructs and those privy to the Destroyer cults.

1. Start from a dark silver base. I use Leadbelcher here.
2. Wash down with Nuln Oil , then again with Agrax Earthshade .
3. Drybrush with a midtone silver, I use Necron Compound here. Drybrush all over the silvers, but concentrate more towards the upper edges of segments and plates to start an exaggerated gradient.
4. Edge highlight the sharp points and edges with Stormhost Silver .
5. Bring back Agrax Earthshade , water it thinner, then introduce toward the lower halves of segments and plates. Draw the brush from where you want the gradient towards the bottom, and cover a smaller area each time you add a new layer. Eventually you get a dirty, tarnished look to the metals

Silver

For the troops that aren't quite important enough to be polished after every fight.

1. Start from a dark silver base. I use Leadbelcher .
2. Wash down with Nuln Oil .
3. Relayer the silvers with Ironbreaker , leaving some wash in the recesess.
4. Edge highlight with Stormhost Silver .

Shiny Silver

For those in your Royal Court.

1. Start from a dark silver base. I use Leadbelcher here.
2. Wash down with Nuln Oil .
3. Relayer with Ironbreaker to bring back the shine. Leave some wash in the recesses.
4. Edge highlight with Stormhost Silver . I also glaze the colour toward the top halves of segments and plates to make it appear overall shinier.
5. Thin down Basilicanum Grey with water and introduce it towards the opposite half of the segments and plates. Try and leave the Stormhost edge highlight at the bottom in tact if you can, but you can simply touch up the colour if you do.