I purchased series 2 & series 3, both in colour, and they did not disappoint. I can remember the series from the 1960's. It was always one of my all time favourite sci-fi series.The picture and sound quality is first rate. The story lines/plots in series 2 are mostly quite believable. Unfortunately, the same cannot be said for series 3, with plots involving werewolves, mermaids and fossil men! I'm sure the young audiences at the time thought they were scary and enjoyable, but watching now as an adult I find them a little cringeworthy. I wonder how the actors took to the scripts? However, all this aside, it is a fantasy series after all. The emergence of the flying sub, and the crew in red/blue dungarees sets these series apart from series 1, which I've not purchased yet. But soon will though, together with series 4!