Overview Bar Back Color

OverviewBarDrawBackColor - controls background color of the Overview Bar.

If true, background color corresponds to current editor window background, this helps too keep similar representation of the objects from document on overview bar.
If false (default), old behavior - standard window background color used (button face).

to enable new behavior add this to settings.xml:

<Source_Editor>
  <OverviewBarDrawBackColor>true</OverviewBarDrawBackColor>
</Source_Editor>

xml option