This is real tricky to get my head round but i might as well take a guess anyway.
Theyre in the desert in Tunsia and so theres this almost tropical light coming in from the window
with greens and purples which changes more to brown in the shade and corners of the room.
As the prints faded its lost some of the green and purples and looks more brown. In the Gout frame it doesnt look like theyre in Tunsia. In your corrected frame it does look like they're in Tunsia but now theres too much colour put back in. This is why all the outside shots look better in your rendering. But it needs to be more subtle now.

Well this is my guess. HELP!