1. Open a demo page having both overview panel and UIO, such as: http://build.fluidproject.org/infusion/src/demos/prefsFramework/
2. Open UIO panel, in "colour & contrast", pick any non-default contrast;
3. Both the main page and the overview panel have the new background colour applied. Without the border of the overview panel having a different colour, the overview panel looks like a part of the main page.