https://megous.com/dl/tmp/2eddfc6ed4ebe129.png
No background difference, nothing. It's not visible when I set monitor to low brightness during the night.
Most installable themes are similarly non-distinct. I had to go through install/uninstall loop of around 15 themes before finding one that has strong contrast on the selected tab:
https://megous.com/dl/tmp/3571258bbc86a7db.png
That's what happens when things have to look pretty, instead of being usable.
But they also ruined the window itself in a similar way. It no longer honors the OS theme, so I can't have the title bar be a different color for the focused window. Another waste of brain cycles trying to figure out which window I'm in.
Maddening. I went back to Chrome when they did this a few releases ago. That, and the fact that I have to drill down into submenus for common tasks that should be available on the main menus.
[1] http://facechance.com/about/ [2] http://facechance.com/bingge
Make of that what you will.
