The basic color scheme of militia units is olive drab with maroon highlights on prominent areas of the unit.
Per Field Manual: 3085, p.185
Other references: none
The base emblem is that of the Republic itself, with the map of Terra replaced by a stylized map of the appropriate world. Around the edge of this badge are the words "Republic Standing Guard", followed by the name of the planet. The ribbon that runs behind the map image may be stylized or colored per local flavor.
per Field Manual: 3085, p.185