It’s 30 years since I saw it, but it was a British film about a small fishing village that tried to save themselves from , perhaps an oil company, by faking a rare species of bird to get some sort of environmental protection.
The film was pretty much about the whole village trying to save their village.
It was probably made in the 1960’s, early British Technicolor equivalent (pretty garish colours).
The end of the film showed a couple finding that the local birds had hatched pink which apparently saved the town. Lovely closing shot (or close to closing shot) of a sunrise.
Thanks for your help – I’m really keen to see this again.