Tooltips don't use system colors

Tooltips, which may pop up when changing to a new id, for example, use modified background and foreground colors. Since here global settings are ignored, the program should provide an interface to customize these colors. Alternatively, this part of the application can be modified to use global color settings like the rest of the application does.

That should apply to all applications in general.

Trac:
Username: FLVkHboLWMq8FoK8