'Post the Colors' is a metaphor used with regard to Flags, Bunting (those '4th of July swags), and items meant to signify the Flag of the United States of America. 'Post the Colors' has always referred to display on inanimate objects.
Wearing the U.S. Flag (which, by the way, is not the 'American' flag -any more than the Flag of Brazil, also an 'American' country) on ones clothing is a personal display of an inward commitment, not an inanimate 'Posting'. The 60's and 70's era were rife with appropriate -and inappropriate, examples, thus the law governing personal displays (I vividly remember seeing the Flag sewn in disrespectful clothing locations on the body) to give School Administrators backing when dealing with such issues.
Reciting patriotic pledges is no different than reciting your last name (a 'Pledge' of respect for your ancestry) or calling someone 'Sir' or Ma-am'. It's called respect, and it's important to pass along. Patriotism is a concept that was historically sacred, not legislated. It was individually understood because it was engrained into the children by their elders.
Show yourselves to be adults with a good grasp of common sense to your children. It is (not only expected by the Scouts' Parents, but) your duty to yourself, and to those you serve.