Icon background color
It would be nice if the white background on geocaching icons could be changed to other colors per folder. I normally have all caches for an area in one folder and other "important" to find caches in another folder. The settings for each folder could have an option for changing the background color.
For this to work, it would also be necessary to control which icon to show on top if the same geocache exist in several folders. A simple solution that does not require any UI could be to draw the icon with white background behind/below icons with color.