So the software worked and ripped (most) of the programs, turning them to mp3 - even the songs, in individual files with titles! (some have a bit of chat at the start/end).
I also found out all the programs are actually still available to listen online ...
There's loads of pictures and stuff on the Couleur 3 website. A great, atmospheric video from 1990 here http://www1.rsr.ch/couleur3/25ans/video.html (the one at the bottom right of the TV screen) with background from Stone Roses and Love & Rockets.
They have also published the list of "reperages" songs that were on the constant playlist, from 1983 to 2000 http://www1.rsr.ch/couleur3/25ans/histoire18.html
This has prompted me to do a massive, 6-CD compilation of the best of those from '89 to '92.
Great fun tracking the songs I'm missing on ebay/hype machine/itunes/torrent. I'm almost there (missing "Mr Odd" from Jazz Butcher, "on fire" by Dave Stewart and "I'll be your chauffeur" from David J, if you can help!)