Regimental colours are the focus of pride in any regiment, they often carry the regiment’s battle honours, and in the days when the flag was carried into battle it acted as a rallying point and a statement of where the command post was, something which could be seen above the mess of battle. Losing a flag was a mark of dishonour to a regiment, capturing one was a point of pride and usually an indicator that the losing regiment had been soundly beaten.
Therefore if we’re going to replicate a true Napoleonic battle we need to have a simple mechanic that can replicate this action. After all, wouldn’t it be nice to have bragging rights over your opponent?
I believe the simplest solution to this would be to have a further additional roll once a melee has concluded. This would simply be a single dice roll for the victor where on a 6 the victor has claimed the enemies colours.
This particular rule will be entirely up to the players whether they use it or not, as its only purpose is to add to the flavour of the battle.