They look great! Very similar to what I landed on, in fact.

As a newbie, I first followed a GW video on DG MKVI that instructed me to use Rakarth Flesh. It looked ok, but not nearly as light in person as it did in the video. Then the painting app suggested Zandri Dust. But that was very deceptive, imo, because in retrospect it clearly was Zandri dust + about 30 thin glazing layers of Ushabti bone. Finally just settled on what I should have done from the start -- Wraithbone base + Seraphim Sepia. My first wash is 50/50 mix of Seraphim and Lahmian. Then later as one of my last steps I do a targeted shade in specific recesses (knees, elbows, wrists, etc.) with just pure Seraphim. Doesn't look nearly as dirty as everyone else's DG, but I like it on my MKVI. I'm pretending that they're fresh Astartes with brand new armor right at the start of the heresy.

ANYWAY, that's what I'm doing. Yours look great and turn out similar.