Softie2 remember though that DarkUI will remember that setting for as long as you play. After you exit the game and restart you have to set it again.
BUT...there are ways to set it permanently. The first one would be by editing a xml file from DarkUI, although in this case i would not know which xml file. (Not very helpfull is it.
)
The second way and in my opinion the easiest way would be to use this mod, it allows you to make permanent changes to DarkUI
ingame.
http://www.tesnexus.com/downloads/file.php?id=34792
These permanent settings can ofcourse be set back to default if you so wish it.