So read the "Color Identity" section here https://magic.wizards.com/en/content/commander-format because it doesn't matter if the mana symbol is present on double-faced cards. Archangel Avacyn (white that flips to red) is the example listed under color identity, and the card is both white and red.
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Just an FYI: you can't have Garruk Relentless in there because it's color identity is green and black. (I am working on a werewolf commander as well, and I really wanted to include him.)