Colors can change in the dark

Slides, negatives and prints all are subject to color changes, even when stored in the dark. The two main effects are color shift and a yellowish haze over the image.

The original (top) exhibits a classic magenta shift, caused by the early decay of the cyan dye. Fortunately, it can be corrected digitally (bottom photo), using our standard service. Photo: our customer LTC Kane.

While these effects might take longer to happen than with typical light fading, they are maybe even more dangerous, since they usually happen to photos that you don't look at often. And so you might be inclined to let the damage go on for too long.

Why images decay in the  dark

Chances are, your old color images were developed and printed using a chromogenic process. This kind of process relies on chemical reactions to produce a set of organic dyes — usually a blue, a red, and a yellow — that in combination produce the colors in your image. But these dyes, as they are the result of chemical reactions, are inherently unstable. Light accelerates their breakdown, but doesn't cause it. So even if you store your images in the dark, so long as they are at typical household humidity and temperature levels, they will eventually deteriorate.

Another side effect is that in many cases the image develops a yellowish haze. This is because in many (but not all) color films used during the period 1936-1990, the yellow dye can increase in density over time. Perhaps the most famous example of this are Kodacolor images from 1942-1953, which had particular problems, due to some of the dye-forming agents (called "couplers") remaining in the print after processing. (For this reason, this kind of color change is often referred to as a "coupler stain.")

How scanning can  help

Scanning, done the right way, can literally save your images. But simply digitizing your existing image isn't enough, since it is likely to have already faded, developed a yellowish cast, or been scratched. So digitizing it only would simply lock the image in its current, deteriorated state.

What's required is that your image be first scanned, then repaired. Many of these effects are straightforward to repair, if the operator is properly trained. At ScanCafe, for example, nearly every image submitted to us has required some level of correction, and we've been able to do the majority of that within our standard pricing, which costs just pennies per image. However, if you wait too long before you scan and repair your image, your image may be deteriorated to the point where it requires a higher level of service from us — we call it restoration. And in the worst case scenario, it may not be repairable at all.

How to prevent color shift of your remaining analog images

Chances are, your analog images stored in the dark are already showing some color shift. However, there are a few techniques that you can try that should extend their life:

• Keep them cold.
  Generally, institutions like NASA and the Kennedy Library in Boston store their color images in refridgerated conditions. Kodak researchers have published data showing that you can increase the life of a color image stored in the dark by at least a factor of 10 if stored at 39 degrees Fahrenheit or less with low relative humidity. Because the stability of films improved somewhat over time, a good rule is: the older the images, the colder they should be.

• Keep them dry.
  A low relative humidity environment is important. Most experts point to 30% as a good number, though this is difficult for consumers to achieve (an ordinary freezer has a relative humidity of about 60%). In the absence of specialized technology, you could simply put them in a freezer but make sure to use (if possible) an airtight container.

• Avoid the basement.
  Basements are almost always humid during at least some months of the year. At the very least, keep your old images in an air-conditioned environment and out of both the attic and the basement.