Good evening from Germany,
Been reading this forum with great interest for quite a while.
Now that I actually can contribute some insight I'll gladly join the conversation
The segment you posted is from the legendary German music show "Beat Club", produced by Radio Bremen (the smallest member station of Germany's public ARD network).
Briefly visible at the start of the video and at about 11:50, the cameras used are Bosch Fernseh KC4 P40 which is quite an interesting thing: Bosch Fernseh was one of the largest camera manufacturers in Europe with a legacy dating back to the 1930's and with an excellent reputation for their b/w cameras.
Unfortunately when color TV did arrive in Germany in 1967 they were stuck in the development of a 3 image orthicon camera which was a "dead end street".
In an act of desperation Bosch Fese hastily issued a modified version of the American General Electric PE 350 in order to have anything to offer to their European customers whom they were losing mainly to Philips.
(Of course when finally introduced in 1969, the 3 plumbicon KCU40 went on to become one of, if not THE color camera workhorse in continental europe in the 70's.)
Here you have some pics of this camera model:
http://www.fernsehmuseum.info/fese-kc-4p.html
The camera shown first two images on the right actually was one of Radio Bremen's. With the model being quite rare and Radio Bremen being so small there's a good chance it actually is one of the cameras used in the production of the Beat Club video.
As already stated the chromakey uses blue instead of green. You actually can see the blue screens in the "fish eye" shots at the beginning of the video and around 12:00.
An interesting observation are the crawling edges of the key layer - look at the stand of the overhead mic at 17:48 - which I tend to interpret as a cross-luminance ("dot crawl") effect. I thus assume that the whole effect production was done using a composite vision mixer.
So - getting back to the original question - what you see is the look of plumbicon cameras, combined with chroma keying, a nice touch of director Michael "Mike" Leckebusch's psychedelic trickery, coming to us on a clean 2" quad color video tape.
Kind regards,
Michèl
P.S. What you see is the actual tape of the session which later was inserted into the final show. Funny that Beat Club and it's successor Musikladen not only have all episodes intact on the program master tapes but even have production elements tapes still existing. Compare that to BBC's Top of the Pops (to make a mean comparison)