Some strange and uniformed comments/criticisms about this excellent series.
One says that was a 'goof' to show prisoners in 'dress uniforms'. A brief search for photos of Colditz prisoners online will show that all POW officers possessed proper uniforms, as under the Geneva Convention these could be requested via the Red Cross. It would have been an unlikely mistake, as Pat Reid was an adviser on the series.
Another says that there were no Americans in Colditz. There were in fact three Americans: Colonel Florimond Duke, Captain Guy Nunn, and Alfred Suarez.
Some liberties were clearly taken for dramatic effect. For example, the famous 'Tea Chest' escape is featured. David McCallum's character, Simon Carter was based on the real Tea Chest escaper, 'The Medium Sized Man' aka Fl Lt Dominic Bruce OBE MC AFM KSG (Wikipedia has a very comprehensive biography, well worth a read) who did not deliberately give himself up as Carter does, but was only caught weeks later in Danzig.
For the most part, this series gives a fairly accurate portrayal of the struggle between the inveterate escapers (you were only put in Colditz if you had escaped from somewhere else, and got caught) and the well trained German security officers.