Here's another variant.... an option to wrap an outline around both the active tab area and the active title:
Looking at the screen shot I can tell having an outline for a tab does look good and this would include segmented tabs style as well.
Aside from doing borders or changing opacity perhaps an easier approach (that would also look good) is simply making the inactive tabs lighter in color similarly to how "darken tittle bar" looks and functions. That way tabs that are all the same color would stick out and an active tab would be darker and more pronounced and all the colored tabs are still visible to their color but just slightly lighter
Of course this already works when transparency is active in the segmented style so the change would be more to the actual color. So it would also work for solid colors and independent of transparency effects.
