To change navigation pane colors you need to access the navigationPane.NavigationBar.ColorScheme object.

C#:

private void Form1_Load(object sender, EventArgs e)
{
    ColorScheme colorScheme = navigationPane1.NavigationBar.ColorScheme;
    // Office 2007, 2010 and Windows 7 styles use global color scheme
    // Note that changes to global color scheme affect all controls that use changed colors
    if (navigationPane1.Style == eDotNetBarStyle.StyleManagerControlled ||
        navigationPane1.Style == eDotNetBarStyle.Office2007 ||
        navigationPane1.Style == eDotNetBarStyle.Office2010 ||
        navigationPane1.Style == eDotNetBarStyle.Windows7)
    {
        Office2007ColorTable colorTable = ((Office2007Renderer)GlobalManager.Renderer).ColorTable;
        colorScheme = colorTable.LegacyColors;
 
        // This is default background color for unselected items
        colorTable.NavigationPane.ButtonBackground = new GradientColorTable(Color.White.ToArgb(), Color.DarkGray.ToArgb());
    }
 
    colorScheme.PanelBackground = Color.Red;
    colorScheme.PanelBackground2 = Color.DarkRed;
}

VB:

Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs)
    Dim colorScheme As ColorScheme = navigationPane1.NavigationBar.ColorScheme
    ' Office 2007, 2010 and Windows 7 styles use global color scheme
    ' Note that changes to global color scheme affect all controls that use changed colors
    If navigationPane1.Style = eDotNetBarStyle.StyleManagerControlled OrElse navigationPane1.Style = eDotNetBarStyle.Office2007 OrElse navigationPane1.Style = eDotNetBarStyle.Office2010 OrElse navigationPane1.Style = eDotNetBarStyle.Windows7 Then
        Dim colorTable As Office2007ColorTable = DirectCast(GlobalManager.Renderer, Office2007Renderer).ColorTable
        colorScheme = colorTable.LegacyColors
 
        ' This is default background color for unselected items
        colorTable.NavigationPane.ButtonBackground = New GradientColorTable(Color.White.ToArgb(), Color.DarkGray.ToArgb())
    End If
 
    colorScheme.PanelBackground = Color.Red
    colorScheme.PanelBackground2 = Color.DarkRed
End Sub

Related posts:

  1. How to Access Office 2007 Color Table
  2. How to customize Office 2007 color table on per Bar or Control instance
  3. How To Customize Office 2007 Color Table
  4. How to Customize DateTimeInput, DoubleInput, IntegerInput and TextBoxX colors
  5. Localizing NavigationPane, NavigationBar