Turbine, please hire a someone with UI design experience for a couple days and use them to avoid monstrosities like this:
This makes me want to puke, the color contrast is so horrible. You've got conflicting things going on here. Dark background for the panel, smaller light background for a sub-panel, a horrible red to highlight title/buttons and too light of a border on the buttons. Too many things are going on at once here, call me crazy but if I stare at this my eyes just kind of lose it...
Something's got to go. Just go back to a simple tan background (it's easy on the eyes) and a less mucky red and you're fine. Remove the dark background (use it as 'empty space' not background color) since it contrasts too much with the rest of the UI, and definitely too much with the game world itself (blue sky, colorful areas etc, see top left corner) and please remove the horrible highlight around buttons (this is worse in the new inventory panel, it makes all the icons look very fake)
/Rant Off
Edit: I never knew there was a User Interface sub forum... mods feel free to move this there(Or move here)