public void SetMenuEnabled(bool isEnabled)
{
   foreach (NCommandContext context in (myCommandManager.Contexts))
   {
       if(context.Properties.Text == "test")
       {
           context.Properties.Selectable = isEnabled;
           context.Properties.Font = new Font(context.Properties.Font.Name, context.Properties.Font.Size, FontStyle.Bold);
       }
   }
}

myCommandManager is an NCommandBarsManager.
When I run this code I get an NullReferenceEception. And when I hover with the mouse, it says that .Font = null.
The setting of the Selectable property works all fine when I comment the .Font line...

How can I set the .Font property?