OK you need to read this carefully; a new process called “colour recovery” is being tested, and could provide us with colour versions of original Doctor Who adventures.
This is a separate process to colourization, and depends on information hidden in telerecordings (the shooting, on 16mm film, of a programme displayed on a high clarity television monitor for sale overseas).
No, it isn’t April 1st.
What we’re looking at here is best but in this article in the Guardian (thanks to Leon Hewitt for the link):
Any black and white telerecording of a colour programme is prone to pick up interference from the colour encoded video signal. This manifests itself as a pattern of small grey dots, called chroma-dots, across the picture. There was a way to stop this from happening, by using a special filter to cut out the electronic artefacts. However, the interference was often deemed so minor that the technicians doing the transfers used no filter and so the resultant film prints often contain a burnt in pattern of these chromadots.
[James] Insell suggested that it might be possible to decode the original colour signal of the show from these chromadots, since they contain an electronic remnant of the original video signal.
“The quality of the film has got to be good enough to have captured this pattern. We’re really talking about working from the original negatives and having an HD scan made to get as much information as possible from the film.” Insell also stresses that the process would only work on programmes that were originally recorded in colour.
Which bodes well for Part 1 of Invasion of the Dinosaurs and various other Jon Pertwee-era adventures which currently only exist in black and white but were broadcast in colour.
It seems also that any success in this is due to BBC technicians using no filters to prevent the “chromadots” from being captured.