protected override void OnRenderSplitButtonBackground(ToolStripItemRenderEventArgs e)
        {
            if (e.Item.Selected)
            {
 
                Rectangle rectBorder = new Rectangle(0, 0, e.Item.Width - 1, e.Item.Height - 1);
                Rectangle rect = new Rectangle(0, 0, e.Item.Width - 1, e.Item.Height - 1);
                LinearGradientBrush b = new LinearGradientBrush(rect, clsClrs.clrSelectedBG_White, clsClrs.clrSelectedBG_Header_Blue, LinearGradientMode.Vertical);
 
                GraphicsPath path = new GraphicsPath();
                path = clsClrs.FillRoundedRectangle(e.Graphics, rect.X, rect.Y, rect.Width, rect.Height, 8);
 
                e.Graphics.FillPath(b, path);
                clsClrs.DrawRoundedRectangle(e.Graphics, rectBorder.X, rectBorder.Y, rectBorder.Width, rectBorder.Height, 8, clsClrs.clrToolstripBtn_Border);
            }
 
            //base.OnRenderSplitButtonBackground(e);
        }

//e.Graphics.FillPolygon(Brushes.Black, new Point[]{new Point(x, y), new Point(x, y), new Point(x,y)});

class MyRender : ToolStripRenderer
{
protected override void
OnRenderSplitButtonBackground(ToolStripItemRenderEventArgs e)
{
base.OnRenderSplitButtonBackground(e);
ToolStripSplitButton item = e.Item as ToolStripSplitButton;
base.DrawArrow(new
ToolStripArrowRenderEventArgs(e.Graphics, item, item.DropDownButtonBounds,
SystemColors.ControlText, ArrowDirection.Down));
}
}