>The primary damage that is done to any film sitting, either exposed or unexposed, is what is called "dark reaction." Dark reaction is the same thing that happens when you expose film to light, only much, much slower. It results in base fog and apparent increase in speed. Base fog diminishes the contrast range of the film. Since color film has at least three different light sensitive emulsions and dark reaction does not proceed at precisely the same speed on each, outdated color film will also experience a color shift as it ages. With color negative film, unless this is far advanced, it can be corrected in printing. Slides, of course will look off color but can also be printed and color adusted either with Photoshop or automated printing analyzers. The effects that the Kodak person were correct but his explanation was technically faulty. The problem is not the dyes but the dark reaction affecting the silver emulsions which only during processing are converted to dye. This is true of negative and transparency films. He is correct that the production and dating on consumer films presumes some color shift before the film is actually exposed and processed. Same for his explanation for pro films.