如何更改ComboBox下拉列表的文字颜色

        private void Form1_Load(object sender, EventArgs e)
        {
            comboBox1.Items.Add("AAAAAAA");
            comboBox1.Items.Add("BBBBBBB");
            comboBox1.Items.Add("CCCCCCC");

            comboBox1.DrawMode = DrawMode.OwnerDrawFixed;

        }

        private void comboBox1_DrawItem(object sender, DrawItemEventArgs e)
        {

            //初始化字体和背景色
            Pen fColor = new Pen(Color.Black);
            Pen bColor = new Pen(Color.White);

            switch (e.Index)
            {

                case 0:
                    {
                        fColor = new Pen(Color.Green);
                        break;
                    }
                case 1:
                    {
                        fColor = new Pen(Color.Red);
                        break;
                    }
                case 2:
                    {
                        fColor = new Pen(Color.Blue);
                        break;
                    }
            }


            e.Graphics.FillRectangle(bColor.Brush, e.Bounds);
            e.Graphics.DrawString((string)comboBox1.Items[e.Index], this.Font, fColor.Brush, e.Bounds);


        }