Basilikoi - Three main vehicle colors: Black, Light Blay, Dark Blay. The predominant infantry color is black. Occasional gold trim for decoration (especially visors and epaulettes on officers), and purple for things related to the imperial family. All their troops are yellows.
Hetairoi: black legs and helmets/visors, dark gray backpacks, and Space Villain torsos. The Porphyrogenitus swaps in purple arms and gold-decorated legs, along with officer-style gold visor and epaulettes.
Stratiotes: Blacktron I kit (all black) with the exception that they replace the old air tanks with brown backpacks, and their officers replace the Blacktron I torso with the Wrench Blacktron I.5 torso.
Scout-Snipers: All black (with added black cloaks) except for the old Endor Luke Skywalker camo torsos.
Assault Teams: All black (any black torso will do, since it's under a black breastplate) with the Space Villain helmet (with black visor).
Commandos: My most colorful unit I think, since they have lots of gray (Lego Studios stunt man torsos and gray balaclava heads with dark gray backpacks).
Naval crewmen: Black and white with some neon-green (they use Blacktron II torsos, black legs, and white helmets with black visors).
TLDR: Infantry wear lots of black, with gold trimmings for officers.
0 Lord, save Thy people and bless Thine Inheritance. To our Rulers grant victories over the barbarians, and by Thy Cross protect Thine own Estate.