Here is a screenshot of a layout in browse mode that uses a custom theme.
The theme has been saved and all tab panel object changes have been saved.
The control shows a green inner shadow kind of look to the tab text of the active tab. There is nothing in the inspector that indicates any kind of shadow or fill in any mode. Setting the fill in active mode does NOT remove the green tint.
FM 188.8.131.523 on windows 8.1.
Here's screenshots of the inspector in all 4 modes just so you don't think i'm crazy