Unit Colours --
No, I don't mean uniform colors. I mean the flags that are with each unit.
The flag to the left is the "national colour" of Saxe-Bearstein. It has the "red bear" that the original mercenary company ("The Bears") carried when the left Switzerland all those centuries ago.
The "field" is grain gold in color in honor of the grain that is brewed into the wonderful beers that Saxe-Bearstein is so famous for. The "grape leaves" in the corners honor the wines for which the principality are also so well known.
Cavalry "colours" (also known as "standards") contain the Saxe-Bearstein red bear in a center oval. The color of the oval and the corner grape leaves is the same as the "button color" of the unit's uniforms.
The major background color of the rest of the cavalry standard is in the regimental color -- the same as their cuffs and other trim. Cavalry standards are square (as are infantry colours) but are smaller than infantry standards.
Infantry standards follow much the same pattern as the cavalry . . . but with the addition of diagonal "rays" in the color of the uniform coat (which is usually red).
Again, the color of the oval is in the "button color"; and the major color of the "cross" is in the regimental cuff color.
I believe that these flags (while totally "made up") are quite successful in representing the "Seven Years War look".