Yes (well, "Reds" and "Blues") - in fact, the first day they did that, Bobby Van explained about the black-and-white TV set problem.
Someone posted a Whew! audience ticket on Facebook which noted "black and white television door prize." I grant you those were still around in '79, but that's one unspectacular prize.
One year later, on NBC's Election night coverage, they misspoke about the B&W gray levels, and had to make a correction. When Tom Brokaw clarified to the viewing audience that "Blue states would be light gray, and Red States dark gray," John Chancellor then said, "Tom, I've got a better idea--for those watching in Black & White, BUY A COLOR SET!!"
Back on topic, the back side of the rotating partition, on the viewers left side of original Dating Game set, was shown in the early days of the show, but not for the majority of the series run.