I’ve been painting my Solar Auxilia miniatures for the Horus Heresy using a bold combination of blue armor and an orange undersuit, combined with simple silver metallics and white details. The blue armor is drybrushed over a Nuln Oil wash, while the orange cloth is washed with watered down grey contrast paint. Here’s my paint list.
Paints used (with Amazon affiliate links):
Blue Armor
Baharroth Blue
Nuln Oil
Skink Blue
Hellion Green (seems to be no longer produced!)
Orange Suit
Jokaero Orange
Basilicanum Grey
Metallics
Leadbelcher
Retributor Armor
White Pipes
Ulthuan Grey
White Scar
Base
Screaming Skull
Vallejo European Dust
Pallid Wych Flesh