What's on my table: Experimenting with Marble

Three different marbles, but which look best with gold armour?

For the Winter I have a whole army of Legio Custodes primed and basecoated in Retributor Armour, and their Dark Art Miniatures Imperial Palace bases primed black.  My intention is to paint the bases with a Marble effect, and since some of the bases have inlays so I will need to combine two marble effects. I ordered some 5 cm perspex discs to experiment on, rather than the actual bases, and whilst I have a lot to learn (rule number one:  work from a picture), the effect is now resembles marble more and tiger stripes less; at least I think so.

I think they all look suitable; but which two to choose?

I have been experimenting with black marble (Nero Marquina), white marble (Calacatta) and red marble (Rojo Alicante).  I have an idea which I prefer for the Custodes, but not my second choice.

Much better than my first attempt, which looked more like tiger stripes

Anyway, here are the paint schemes.  The glazes are applied sporadically in random patches with a shade or no 3 brush, and are very thin indeed.  Finally, two coats of watered down 'Ardcoat are applied to obtain the glossy marble effect.

Calacatta:

Basecoat:  Ulthuan Grey
Thinned glaze: Celestra Grey, Lahmian Medium and Water
Veins:  Dawnstone with Eshin Grey accents

Nero Marquina:

Basecoat:  Abaddon Black
Thinned glaze: Eshin Grey, Lahmian Medium and Water
Veins:  Celestra Grey with Ulthuan Grey overlay

Rojo Alicante:

The Rojo Alicante was difficult because the main colour is more like Martian Ironcrust: a pinky, orangey red.  After much experimenting I settled on:

Basecoat:  Bugman's Glow with a touch of Mephiston Red.
Thinned glaze: Bugman's Glow, Lahmian Medium and Water
Veins:  Ushabti Bone and Ulthuan grey