If you look at the attached image, it is difficult to tell at first glance which button (Filename, Content, etc.) is selected since they look similar to tabs. If you followed the indicator for tab focus, you'd think the button Content was selected, not Filename. It would be nice if the buttons were tweaked somehow--perhaps a blue (with Breeze) frame around the depressed buttons?

Here's the image: https://dl.dropboxusercontent.com/u/1115210/snapshot12.jpeg

Hi
I agree it looks confusing. But then the whole ui is
From top to bottom: toolbar, tabs, line edition, toolbar, list, line edition.
Bit of a mess if you ask me.
I am not sure if having more distinct visual elements will help ...
Also, I wonder how it looks with other widget styles (oxygen ? Fusion ?)

Originally in breeze, checked toolbuttons were rendered with a blue filled squared. This was turned to (the same) grey (as for tabs) because blue was found to be too distracting in "normal" use cases ...