Sir David Attenborough's first TV wildlife show is to be screened in colour to mark his 90th birthday.
The 1950s series Zoo Quest originally aired in black and white, but when footage was unearthed in the BBC vaults last year it emerged that it had actually been shot in colour.
Sir David said: "I was astonished when someone said we've got nearly all the film of the first three expeditions you did in colour.
"I said, 'It's impossible, we shot in black and white'."
Zoo Quest In Colour will be screened on BBC Four in May as part of a week of programming across the BBC to mark the veteran naturalist's milestone birthday on May 8.
First broadcast in December 1954, Zoo Quest was one of the most popular television series of its time and launched the career of the young David Attenborough as a wildlife presenter.
The series was broadcast 10 years before colour television was seen in the UK.
Using the newly-discovered colour 16mm film, together with behind the scenes stories from Sir David and cameraman Charles Lagus, the special will showcase the best of Zoo Quest To West Africa, Zoo Quest To Guiana and Zoo Quest For A Dragon in HD colour.
Lagus said: "At its best it's as good as any colour you see now, quite staggering for the period that it was filmed in. I was astonished."
Other programmes to be screened as part of the week include Attenborough At 90 on BBC One, which will see presenter Kirsty Young talking to the broadcaster about his career and some of his animal encounters across the world.
BBC Two will screen Life That Glows, in which Sir David looks at creatures such as glow worms, fire flies and luminous plankton to guide viewers through the world of bioluminescence.