Here are some interesting facts about the movie from IMDb.
1.The much admired Himalayan scenery was all created in the studio (with glass shots and hanging miniatures).
2.The backdrops were blown-up black and white photographs. The art department then gave them their breathtaking colors by using pastel chalks on top of them.
3.Because of the Technicolor camera and film stock, the sets needed an astounding 800 foot-candles (8,600 lux) of illuminance just to operate at T2.8, which was the widest lens aperture setting.
4.Jack Cardiff said that the lighting and color palette of this film was inspired by the works of 17th-century Dutch painter Vermeer.
5.Jack Cardiff came up with the idea of starting the rainfall end scene by first having a few drops hit the rhubarb leaves before cueing a full-force rainstorm. He personally created the first drops with water from a cup when the scene was shot. Michael Powell was so pleased with the effect that he decided to make the scene, originally the penultimate one, the closing shot. Cardiff, however, was a great fan of the original scene (which had already been shot) that was supposed to follow this one and close the film. To this day Cardiff amusingly calls the opening drops of the rainfall "the worst idea I ever had".