Thanks- after hearing variations of this kind of voice-over at the end of shows telecast during that period, I feel it's somewhat....authentic (NBC did stress the words "in color" during those audio promos).
8:55- "Now stay tuned as Robert Culp and Bill Cosby co-star in the season's most-talked about new secret agent series, 'I SPY', in color. Scott and Kelly search for missing microfilm in Japan, and endanger the life of a deceased agent's girlfriend in the bargain...next. And later, be sure to watch 'THE TONIGHT SHOW STARRING JOHNNY CARSON', in color...on NBC".