Let's rewind to 1962. In Sweden at the time there was only black and white television (and just one channel). On April 1st 1962, the station's technical manager, Kjell Stensson, guested on the news to reveal brand new technology that could transform their old TV into a colour one just putting a nylon stocking over the screen.
Thousands fell for it, but it took another eight years before colour TV became a reality in Sweden on April 1st 1970 (this time it was no hoax).