Prussia Military Sources
Prussian Infantry in the Napoleonic Wars: napoleonistyka.atspace.com/Prussian_infantry.htm#_landwehr .
Prussian uniforms: homepage-andreas-meininger.de/DER_BUNTE_ROCK_1800_bis_1863.htm#Preussen
Here is a story from a FamilySearch Wiki user that is worth considering as well:
It has been said over and over again that you cannot find your ancestor's war record unless you know the regiment or the name of the commanding officer. This is not always the case. I knew neither one of these, but I did know the name of the area in which my ancestor lived in West Prussia. I found a book on line at the University of Michigan which lists all the Prussian Army Corps, Divisions, Regiments etc. I looked up the name of the area where my ancestor lived and it said Army Corps 1, Division 2, Regiment 5. I went on Family search.org and found the film and ordered it and there was my ancestor's war record which I had been looking for, for about 20 years. I thought this might help others who are looking for Prussian War Records. Check it out! http://www.lib.umich.edu/
In the general search field enter "rangliste" Scroll down to #6 and click on "Rangliste der Koniglich Preussischen Armee" Find the year or (approximate years) you think your ancestor was in the army. Click on that year/s and scroll through the book until you find the area listed where your ancestor lived. It will tell you what regiment he was in. Using my information from above, go to familysearch.org and search for Danzig in the catalogue. When Danzig comes up look to see if they have a film with regiment 5.
Multiple locations are available to search. Be forewarned, much of the page is in German as you do your search. Use a translator such as Google's translate to help.