Those are the guys I was referring to. Wikipedia says "Das Freikorps rekrutierte sich ausschließlich aus Freiwilligen. In seinen Reihen dienten neben Preußen auch Bürger anderer deutscher Staaten, die dem Rheinbund angehörten oder wie das Herzogtum Oldenburg und die Provinz Westfalen von Frankreich annektiert waren.", and I don't know for sure, but suspect, that the fact that the volunteers came from various different parts of the country, has something to do with the use of the colours for the unified state - but you are way more of an expert there.
The fool hath said in his heart, There is a God. They are corrupt, they have done abominable works, there is none that doeth good.
Psalm 14, KJV revised edition
