well just for \"joelvanderveen\" and others, i dont know exactly when the color change of the whole set was done, but they were in the process in mid 75 (the classic TPIR episode from 2002), shows the borders around the turntable are green, but the rest of the turntable is still brown and orange. It looked a little wacky. Id say they changed the whole set just before the hour long or for it.
Another question is, when did they change the music. People say that the opening music was changed in 1976, others say in 1975. They were still using the old one on the first hour long episode, and also the \"Patricia Bernard\" episode (dunno if it was hour long or 30min, im saying hourlong though, had the red and green set, and the old music\".
So i guess everything was changed about late75-mid76