Lack of distinction for focused tab on unfocused group.

[wkrueger]

Let's say we have two groups of tabs, one to the left and one to the right.

When the right tab group is focused, I can't know which of the tabs of the left group is being displayed.

In the sample image above, the "index.js" tab is focused but the only highlight for it is the X button which is kinda too subtle.

Comparison to other theme: