California Code, Probate Code - PROB § 5031

(a) If a married person executes a provision for a nonprobate transfer of community property on death with the written consent of the person's spouse, the consenting spouse may revoke the consent by a writing, including a will, that identifies the provision for transfer of the property being revoked, and that is served on the married person before the married person's death.

(b) Revocation of a spouse's written consent to a provision for a nonprobate transfer of community property on death does not affect the authority of the holder of the property to transfer the property in compliance with the provision for transfer of the property to the extent provided in Section 5003.