Question: Why does this serial only survive in black and white. If it was made in colour, why did the BBC have black and white copies in the first place?
Doctor Who (1963)
1 question in season 8

Other mistake: The Brigadier says UNIT HQ is 'a Top Secret establishment'. It is, in fact, so secret that it has a large sign outside informing the world not only of its function, but also the name of the commanding officer.
Castrovalva - S19-E1
The Doctor: That's the trouble with regeneration, you never quite know what you're going to get. (00:12:15)
Trivia: Such was the popularity of Doctor Who in Britain in the mid-1960s that even the Beatles wanted to make an appearance in the show. So a scene was written into "The Chase" to allow them to appear. The idea had been devised of including a scene on the Time and Space Visualiser depicting a Beatles fiftieth-anniversary concert in 2015, with the Fab Four dressed up as old men. John, Paul, George, and Ringo themselves were interested in the proposition, but it was vetoed by their manager, Brian Epstein. It was then thought that an appearance by the Beatles on Top of the Pops might be used instead, but no such footage was available. Fortunately, the Beatles were scheduled to perform "Ticket to Ride" at Riverside Studios in Hammersmith on April 10th, 1965, and that footage was used instead.





Chosen answer: The reason this serial only exsists in black and white when it was recorded in colour is because in the 60's and 70's the BBC wiped and reused video tapes, some of which were Doctor Who. Luckily copies were made and sent to other countries, most of which didnt have colour TV's. These copies were later found and returned to the BBC archive.