I use a lot of washes/glazes on my Ultras.
The golds have a chestnut wash on them.
Silvers/greys (just the krack grenades on these guys) get a nulan oil.
Base blue is Macragge, and these guys have a drakenof nightshade wash over that blue. Most of the time I use an old pot of Blue Ink, but I was almost out when I started painting my 30k guys, so they got the nightshade. I’ve since acquired a new pot of the old ink, so am back to a more brilliant sapphire blue on most of my guys.
From left to right:
Guiliman blue glaze
Blue Ink (from the Cote D’arms days)
Drakenhof nightshade
You can also see in that picture how the modern washes flow differently then the inks/glazes. They do, in fact, go into the recesses better to add shading, while the ink/glaze does this a little, but alters the color more then adds depth.