Restoration of natural colour film – Introduction.
In 1918 William Kelley, subsequently the inventor of Kelleycolor, writing in the Transactions of the Society of Motion Picture Engineers, complained that he had several times been attracted to a cinema where colour films were advertised only to find that the film was coloured black and white. He was not the first to want to distinguish between "real" colour films and tinted, toned or stencilled black and white films, which were far more common at that time.
Kelley proposed that films be called "natural colour" for the first and "coloured" for what he described as "films arbitrarily coloured by dyes.... to suit the individual taste".
The problem still exists today and we often still use Kelley's terms, in English, to distinguish between coloured films and natural colour films.
Natural or photographic colour film systems can be defined as those that have an analysis and a synthesis stage, and in which the reproduction attempts to stimulate the human eye in a manner similar to that of the original scene.