One more thought. UV protection doesn't stop their fading completely. It just helps alot.

UV is the most obvious source of fading. The shorter wavelengths of visible light (blue, violet) are still energetic enough to cause some fading.

I have a display window with 99% UVF architectural glass. We still have to watch how long things are in that window as the sun sets on it every day. I've seen frames change color,etc.

Museums keep track of illumination levels and number of hours of exposure. Ignoring any reciprocity effects (related to, but different from our own film concerns), 100 footcandles x 1 hour = 1 footcandle x 100 hours.

You can't enjoy them if you keep them in the dark, but just keep in mind that 'protection' is relative, not absolute.