STGN is absolutely correct!
The basic resistance pattern is very close to Alpenflage so it probably is, but alpenflage is based on the end of the war Nazi pattern called Leibenmeister (?sp?) pattern and was also used by the czechs (which may be the case in OFP since it is a Czech game) and Belgian armies for a while, but like Stgn said it is most probably Alpenflage varaiation although they are all identical for the most part. All the Resistance wear flecktarn hats though.
DL ;D