Sweden's most famous April Fool's Day hoax occurred on April 1, 1962. At the time, the only television channel in Sweden announced to describe a process that would allow people to view color images on their existing black-and-white sets.
SVT (Sveriges Television) was the only television channel in Sweden, and it broadcast in black and white.
The station announced that their "technical expert," Kjell Stensson, was going to describe a process that would allow people to view color images on their existing black-and-white sets.
The broadcast cut to Stensson sitting in front of a television set in the studio. He began to explain how the process worked. His discussion was highly technical, going into details about the prismatic nature of light and the phenomenon of "double-slit interference." But at last, he arrived at the main point. Researchers, he said, had recently discovered that a fine-meshed screen placed in front of a black-and-white television screen would cause the light to bend in such a way that it would appear as if the image was in color.
Stensson told viewers they could experience the effect at home with the help of some simple, readily accessible materials. Nylon stockings, it turned out, were the perfect fabric to use as a fine-meshed screen. So all viewers had to do, Stensson said, was to cut open a pair of stockings and tape them over the screen of their television set. The image on the television should suddenly appear to be in color.
Stensson cautioned that the viewer would have to be seated at the correct distance from the screen to get the full effect. Also, it might be necessary to "move your head very carefully" back and forth, to align the color spectrum.
Thousands of viewers later admitted they had fallen for the hoax. Many Swedes reported that they remember their parents (their fathers in particular) rushing through the house trying to find nylon stockings to place over the TV set.
SVT attempted its first color broadcast four years later, in 1966. Regular color broadcasts were begun in Sweden on April 1, 1970.