I think this skin could benefit a lot from the new elements "to override the tabs bar when docked in the caption bar and the player is docked at the top":
<element id="TabsBar.TabInCaptionBarTop.Default" bg="15,215,215" fg="30,30,130" bdr="170,10,170" />
<element id="TabsBar.TabInCaptionBarTop.Highlight" bg="145,245,5" fg="220,220,20" bdr="10,10,190" />
A unity aspect with the currently active tab, and darker inactive tabs would be pretty nice