Series one of this programme was made before July 1969 and as ITV (in this case Thames Television) and BBC1 only transmitted in black and white it was produced in monochrome.
Series 2 was made in 1971. At this time ITV had a technician strike regarding working the new colour cameras. As such many programmes were recorded in Black and White until the dispute was resolved. Upstairs Downstairs was similarly affected. (London Weekend Television).
Series 2 was made in 1971. At this time ITV had a technician strike regarding working the new colour cameras. As such many programmes were recorded in Black and White until the dispute was resolved. Upstairs Downstairs was similarly affected. (London Weekend Television).