lz那样设置BackColor是没有用的，要使用ToolStripProfessionalRenderer和ProfessionalColorTable才可以，参考下面的示例吧：
如何：自定义ToolStrip应用程序中的颜色
通过使用ToolStripProfessionalRenderer类以使用自定义颜色，可以自定义ToolStrip的外观。
示例
下面的代码示例演示如何使用ToolStripProfessionalRenderer在运行时定义自定义颜色。
// This code example demonstrates how to use a ProfessionalRenderer
// to define custom professional colors at runtime.
class Form1 : Form
{
public Form1()
{
// Create a new ToolStrip control.
ToolStrip ts = new ToolStrip();
// Populate the ToolStrip control.
ts.Items.Add("Apples");
ts.Items.Add("Oranges");
ts.Items.Add("Pears");
ts.Items.Add(
"Change Colors",
null,
new EventHandler(ChangeColors_Click));
// Create a new MenuStrip.
MenuStrip ms = new MenuStrip();
// Dock the MenuStrip control to the top of the form.
ms.Dock = DockStyle.Top;
// Add the top-level menu items.
ms.Items.Add("File");
ms.Items.Add("Edit");
ms.Items.Add("View");
ms.Items.Add("Window");
// Add the ToolStrip to Controls collection.
this.Controls.Add(ts);
// Add the MenuStrip control last.
// This is important for correct placement in the z-order.
this.Controls.Add(ms);
}
// This event handler is invoked when the "Change colors"
// ToolStripItem is clicked. It assigns the Renderer
// property for the ToolStrip control.
void ChangeColors_Click(object sender, EventArgs e)
{
ToolStripManager.Renderer =
new ToolStripProfessionalRenderer(new CustomProfessionalColors());
}
}
// This class defines the gradient colors for
// the MenuStrip and the ToolStrip.
class CustomProfessionalColors : ProfessionalColorTable
{
public override Color ToolStripGradientBegin
{ get { return Color.BlueViolet; } }
public override Color ToolStripGradientMiddle
{ get { return Color.CadetBlue; } }
public override Color ToolStripGradientEnd
{ get { return Color.CornflowerBlue; } }
public override Color MenuStripGradientBegin
{ get { return Color.Salmon; } }
public override Color MenuStripGradientEnd
{ get { return Color.OrangeRed; } }
}
