This guy was Brother Potter in the early catalogues, later shown as Bionic Eyes and Bolter 070106/4. He’s a 1987 sculpt.
Undercoat: Vallejo Mecha Black
Blue: Scale75 Artist Cobalt shaded with Prussian Blue, highlighted with Primary Blue and then a mix of Primary Blue and Art White
Skin: Light Skin mixed with Artic Blue, highlighted with Golden Flesh and Art White, shaded a little with diluted Dark Brown Ochre.
Red: Light Skin followed by Primary Red, highlighted with a mix of Primary Red and Orange. Washed with Nuln
Silver: Black Metal, with Nuln oil wash, then Heavy Metal, Speed Metal and White Alchemy
Varnish: Vallejo Mecha Matt Varnish
Black: Art Black, highlighted with Artic Blue
Green: Sap Green, highlighted with a mix of Sap Green and Primary Yellow
Leather: Burnt Sienna then Burnt Skin, highlighted by a mix of Burnt Sienna and Orange