
Artifact — Equipment
Equipped creature gets +3/+3 and has protection from each color that's not in your commander's color identity.
Equip commander
Equip

Cheap equipment granting hexproof and haste to protect commander.

Free equip with shroud and haste for commander protection.

Buff equipment granting protection and value, similar protective role.

Powerful equipment buffing with protection and card draw.

Grants unblockable and shroud to equipped commander.

Cheap equip granting +2/+2 and hexproof, commander-focused.

Cheap equipment giving evasion and damage prevention protection.

Equipment buff giving +3/+0, trample, lifelink for combat dominance.
If you have no commander, Commander's Plate grants no protection abilities. The equipped creature still gets +3/+3.
If you have two commanders and attach Commander's Plate to one, it has protection from each color not in your two commanders' combined color identity.
If your commander is a card that has no colors in its color identity, Commander's Plate gives it protection from each color.