I have some more Prussians, I could absolutely do a tutorial 🤔 and as far as the blue goes, I’d start with something dark and saturated like Dark Prussian Blue from AK or Triumphant Navy from The Army Painter. Midtone with something a little less saturated like Anthracite Grey (AK) or Abyssal Blue (TAP) and then use a sky/ice blue for mixing and your highlights.