
I'm developing a VSTO plugin for Outlook 2016 but am not able to change the border and header background color (as you can see from the linked image).
I tried to force the "BackColor" property of the TaskPaneWpfControlHost object but what happens is that I get the background change of the user control injected into the container.
public TaskPaneWpfControlHost(System.Windows.Controls.UserControl shell)
{
this.BackColor = System.Drawing.Color.White;
InitializeComponent();
wpfElementHost.HostContainer.Children.Add(shell);
wpfElementHost.AutoSize = true;
wpfElementHost.Dock = DockStyle.Fill;
_shell = shell;
}