The site Viewing Japanese Prints has two excellent articles on fading in Japanese prints. The first shows three prints, displayed above, by the same artist and from the same time frame that reveal the changes in color that occur over many hundreds of years, especially in the colors of earlier Ukiyo-e prints.
The second is even more provocative.
This one tracks a single print and its display over about a decade. In this case the print was out in the open but not exposed to any direct sunlight. Even with the lack of direct light the print still faded significantly (losing much of its dark red and purple). This is certainly a harrowing reveal for anyone that is interested in displaying prints in their home.