Introduced by Eastman Kodak in the 1920's, this film format was initially targeted at the home enthusiast. My grandfather had a 16 mm camera (pictured on the right) and I've converted a number of his old reels that he had spliced onto larger reels. This film is wider and came with an optical sound track (if you had the extra money for it) and in the 1930's was making huge inroads into the educational market. The professionals always considered this format to be inferior but it was used extensively during WW2.
Over a period of many decades, the dyes in color 16mm film slowly degrade and become transparent. The dyes degrade at different rates with magenta being the longest-lasting. This inevitably results in color film that now appears to be reddish, with few other colors. In the process of digitizing old film into a modern digital movie format, the faded film can sometimes be restored to full color with the use of digital color enhancement methods that amplify the faded dye colors, but do not amplify the red dyes.