Those of us in the R65 Asylum welcome you, robalou. Are you perhaps related to the famous Bobalou?

Oh, never mind...
You're '79 R65 may still have a paint code sticker somewhere under the seat; likely stuck to the fender, or...? This could help you determine the exact color if indeed you still have the OEM paint on the bike. Any pin stripes on the tank and tail piece? A helpful site for paint info is Phil Hawksley's BMW Information website.
http://www.bmbikes.co.uk/The R65 Photo gallery works, or you might want to investigate Photobucket
http://photobucket.com/ as a free resource and an easy way to store and post photos to this forum.
Be sure and service your new ride with new lubes in all the right places and set the valves. You'll want a maintenance baseline established; no matter what the PO may have shared with you. Trust, but verify. [smiley=thumbup.gif]
Flat top Bings and a points ignition. Classic.
Monte