When the series made the transition to color,some of the furniture in the house changed.The telephone in the color episodes looked more up to date.And the big leather livingroom chair appeared to be a dark black in the original black and white episodes.It appeared to be the same shape and size in the color episodes,only it was now a strikingly bright red color.I guess the set designers wanted to make the house more colorful if the series was to become a color show.