According to my "Airheads from /5" history book, the R65 in 1979 was available in
silber (548)
and
orangemetallic (551) braune Bank
and for the 1980 model year, they claim , the (in)famous bronco-brown,
"bronco-anthrazitmetallic (589) (braune Bank)
was added.
I think that these were European market colors though - as Rob's I think was bronco-brown and a '79, correct ?