MahApps/MahApps.Metro — pull request #315 by programatix (2013-01-17 10:42:15+00:00)
Title: Update MahApps.Metro/Styles/Controls.ContextMenu.xaml

When a sub menu is popped-up, it's foreground colour would follow the parent. Since the parent's foreground is white, its foreground is also white. The update force the foreground colour the dirty way.