Currently, the user can't modify the background colors and gradient background colors in StdMultiWidget. There should be a preferences page that allows the user to change the colors. For that, QmitkStdMultiWidgetEditor must set and read the preferences and a QmitkStdMultiWidgetEditorPreferencesPage should provide the gui for the user to edit the color values.

It should be possible to:

• switch between unicolor and gradient color for each render window
• set the unicolor / gradient colors separately for each render window