If no modified system files are used:
Originally Posted by Ivo
That is AeroLite theme.
You can switch it on or off manually by first saving your theme and then edit the *.theme (you may need to extract the *.deskthemepack or *.themepack file with 7-Zip first).
This is default to any theme:
The taskbar text is White here.
And this is aerolite:
The taskbar text is Black here.
Save the changes and reapply the theme.
This works on Win8 only.
EDIT: I see I posted too late about aerolite.
But I hope Classic Shell will recognize the theme since some of us like it.