The passing of colors, standards, or ensigns from an outgoing commander to an incoming one ensures that the unit and its soldiers is never without official leadership, a continuation of trust, and also signifies an allegiance of soldiers to their unit's commander.
Great symbolism is attached to the ceremonial aspects of a change of command.
[1] An inspection and review of soldiers, gun salutes, as well as a military band will often be incorporated into the ceremony.
[2] On the International Space Station, the new and old commanders ring a bell.
[3] For a Command Sergeant Major, the transferred item might be a saber during a Change of Responsibility, while for a Chaplain, the item might be the passing of a Clerical Stole.