Also, be aware that the color guard is attached to the company with the 3rd most senior captain (generally, but more specifically they should be on the left flank of the right-center company in battalion line), but that is not the 3rd company. Companies are numbered right to left 1-10. In a 10 company battalion, the colors should be on the left flank of the 5th company (which is generally called the color company). Because of how the seniority of captains works, this usually means the 3rd most senior captain has his company placed in the center (about) of the line (5th/color company). As promotions, deaths etc... take place that means the companies can be moved about in the battalion line (of course not while in battle, but whenever time is available for reorganizations etc...). I hope this helps a bit.
Josh Bucchioni