This guy was the Captain in the 8-man C100 set, which pre-dates Rogue Trader. He’s later shown as Bionic Eye and Power Glove, part number 070121/40.
Undercoat: Vallejo Mecha Black
Base coat: Scale75 Artist Cobalt, shaded with Prussian Blue, highlighted with Primary Blue
Red: Kimera Toulidine Red (PR3)
Black: Scale75 Art Black
Skin: Kimera Diarylide Yellow mixed with Scale75 Art White as the base coat. Then Vanilla White mixed with Art White, with an attempt at shading with Targor Rageshade.
Silver: Scale75 Black Metal
Gold: Scale75 Necro Gold, washed with Targor Rageshade, then Elven Gold, then Citrine Alchemy