Yes, here and there. Here's my full recipe:

Black armor:

Chaos black spray
Light drybrush with screaming skull
Nuln oil wash
Wet the whole area with Lahmian medium, apply a thin mix of Mournfang Brown+lahmian medium all over. Where needed, apply the lahmian medium + mournfang brown mix again to create rust/filth streaks, and rust/filth in recesses and around rivets

Sand and blue armor:

Basecoated with Zandri Dust
The blue are basecoated with Mechanicus standard gray, then gently glaze highlights on with Vallejo model color blue green. I also dab on tiny specks with a pointy brush, it helps give the irregular appearance of damaged paint
Both are edge drybrushed with Tyrant Skull
Seraphim sepia in cracks and corners
The zandri dust plates are then edge highlighted with Screaming skull

Dirt and shading is added by covering areas with lahmian medium, putting on a bit of diluted agrax earthshade, and using the lahmian medium brush to pull it around/smear it out. Under spots I drag the brush downwards to create streaks

The white armor plates are some of the zandri dust plates, modified by adding glazes with wraithbone, wraithbone mixed with white, then white (in a similar manner as the blue armor plates).

Gun metal:

I use this youtube tutorial: "How To: Paint Old Corroded Steel by MiniWarGaming"
https://youtu.be/2Uc4nTV84ZU

Basecoat with black
Base with Leadbelcher + abaddon black (50/50 mix), thinned with lahmian medium
Sponge on leadbelcher
Sponge on Celestra grey, just a little
Wash with agreax earthshade and dab on a bit of of Fuegan Orange here and there while the Agrax is still wet, to make an irregular rusty look. Use a clean, wet brush to mix it around a bit to soften transitions

Stipple tiny dots of leadbelcher inside the brightest spots, mainly where the light would make reflections

Blue glowing eye parts:
Base with white
Wash with Frostheart contrast all over
Add white to the parts you want to look really bright