I looked up Edward Woodward on IMDB and Callan was in 1974.

Regarding TV shows, I left home to live in a shared student house in early 1974 and didn't have a TV until about 3 or more years later in a different shared house. We rented a black & white TV because two of us were desperate to watch Dr Who. (Is that a sad indictment on both of us or a badge of honour? LOL)

We couldn't afford to rent a colour TV so B&W was better than none.

I had been watching Dr Who since it started, when I lived at home. We had a TV from 1964 as I recall and my sis and I used to watch Dr Who starring William Hartnell after school.

Another B&W sci-fi TV show I used to watch back then was The Outer Limits and I have a vague recollection that there was a spin-off series with a different name but it wasn't The Twilight Zone because that wasn't on TV in our region back then.