Well, your message made do a quick search on the internet. This site
http://www.warbirdsresourcegroup.org/LRG/markings.html mentions that both colors were used by geschwader and gruppestab. So both colors are right while I believed there was a difference.
I know blue was used as color for a 4th staffel in a Jagdgeschwader. In a bomber unit a 4th staffel could be recognized by the 4th digit in the ID nr
Thanks for the feedback
groeten