This is due to a bug in Microsoft's themes API. We delegate the drawing to these APIs and they seem to ignore the settings and always the default blue scheme is used.
In the mean time we have logged this as a feature request to our known issues database.
> I know that XPTaskBar supports ThemesEnabled. I notice that whenever I change the windows xp theme that I have, It does not change the color of the Syncfusion XPTaskBar theme. Any ideas?