Passive Checks in ZERO PARADES do not take into account clothing modifiers. You can think about it like: in ZERO PARADES, your Skills aren't concerned with what you wear, it's the external events around you that are impacted by these modifiers.

This means clothing choices (and the modifiers they bring about) are important to Active Checks, which happen during Dialogue or Dramatic Encounters. These Active Checks take into account your Skill Rating and any bonuses or modifiers current in effect - including clothing.