Mark
The colour of the early German uniform was a greener colour than those manufactured mid 1943 onwards. The early uniform had the dark green collar whereas the latter pattern was greyer and had the field grey collar.
I don't have the DML Karl so I can't look at the crew supplied, but based on the box art I can see on the net, it would appear the early pattern uniform, with dark green collar has been depicted.
If so, don't worry. I doubt that these guys would be a priority to get a replacement uniform and would probably have had the earlier uniform even in late '43.
Happy Modelling
Peter