If a card has hybrid mana costs, and can be either a color that is or isn't that of your commander, can it be in the deck and the second color just ignored?
Relavent example: Commander {Wort, the raid mother} and {Murderous Red Cap}
If it were up to me (and MaRo) you would be able to, but alas no. You can't have anything with a color identity outside of your commander's identity. ðŸ˜
Curses! ðŸ˜