This looks really great - I like such dark GUIs a lot!

One question though: I and several other users I spoke to have a problem with the "tabs" in MoI.
To me, the brighter tab looks selected, not the darker one. No matter how many years I'm using it, I still get it wrong half the time. When there are three tabs next to each other it's a bit easier to get right, but with the Construct/Transform pair, I personally never have a clue which one is supposed to be active - I need to look at the available tools to understand it.
Recently I taught MoI to a woman who is really fluid using all kinds of software and it was interesting to see how even after a week of using it she still got it wrong most of the time.

It's one of the major design flaws for me in the MoI GUI actually - the tabs are not tabs at all, since they visually don't connect to the box they are attached to (they are closed at the bottom and don't have the same colour as the background of the box they are supposed to represent), nor are they changing to different front/back looks nor is the colour really obvious.

Your design does the same to my brain - the selected tab looks unselected to me.

So I wonder: Is it possible to have the selected tab open at the bottom and use the same background colour as the box it connects to while unselected tabs are darker (basically like CS6)?

Tabs are a funny thing, they either work directly on the brain stem or they don't work at all and need active thinking - which goes against every GUI-design-grain I have ;-)

Cheers,

Tom