Taking good photos off a TV screen was never easy, less so in the 50's. The sets were usually white balanced quite blue (9300 kelvin) for starters, plus the popular color films generally had poor response to the red phosphor. Kodak published suggested filters to use as a starting point. So, if you just pointed your camera at the set, the results weren't likey to correspond to what you saw.
The closest you can come to experiencing what the color looked like is, as you said, replaying one of the early taped programs. The most salient characteristics of these sources have to do with the image-orthicon cameras. (Rather noisy, and the color response determined by the optical filtering, since electronic matrixing wasn't available). I've always thought the Peter Pan special starring Mary Martin is probably typical.
