Colour film

A film that carries one or more emulsions which after processing carries a record of the colours in the original scene. This may be a negative (opposite) or a positive record.

Colour film has a more complex structure than black and white film. It can consist of many layers.

It consists of as many as nine layers with different functions:

• a protective layer of clear gelatin;
• a blue-sensitive recording layer consisting of gelatin in which silver salts and a colour coupler are embedded;
• a yellow filter layer which absorbs the blue rays of light not absorbed in the blue-sensitive layer but lets through the green and red rays;
• a green-sensitive layer;
• an interlayer of prepared gelatin which prevent dyes produced, especially during development, from migrating from their own layer and hence spoiling the image;
• a red-sensitive layer;
• an adhesion substratum;
• the base or support is usually made of cellulose triacetate or polyester ;
• an anti-halation layer which may also serve as an anti-curl layer.

https://www.nfsa.gov.au/sites/default/files/uploads/2010/10/05/colourfilm.jpg

Learn more about the history of colour in film in this web resource developed by Barbara Flueckiger, professor at the Institute of Cinema Studies, University of Zurich.