C# สอบถามเกี่ยวกับการใส่สี ให้ combobox แต่ละอันให้เป็นสีคนละสีกันครับ

private void ComboColor()
{
comboBox1.Items.Add(""); comboBox1.Items[0].Attributes.Add("style", "background-color: red");
comboBox1.Items.Add(""); comboBox1.Items[1].Attributes.Add("style", "background-color: blue");
comboBox1.Items.Add(""); comboBox1.Items[2].Attributes.Add("style", "background-color: blue");
comboBox1.Items.Add(""); comboBox1.Items[3].Attributes.Add("style", "background-color: blue");
comboBox1.Items.Add(""); comboBox1.Items[4].Attributes.Add("style", "background-color: blue");
comboBox1.Items.Add(""); comboBox1.Items[5].Attributes.Add("style", "background-color: blue");
comboBox1.Items.Add(""); comboBox1.Items[6].Attributes.Add("style", "background-color: blue");
comboBox1.Items.Add(""); comboBox1.Items[7].Attributes.Add("style", "background-color: blue");
comboBox1.Items.Add(""); comboBox1.Items[8].Attributes.Add("style", "background-color: blue");
comboBox1.Items.Add(""); comboBox1.Items[9].Attributes.Add("style", "background-color: blue");
}

private void comboBox1_DrawItem(object sender, DrawItemEventArgs e)
{
    int index = e.Index >= 0 ? e.Index : 0;
    var brush = Brushes.Black;
    e.DrawBackground();
    e.Graphics.DrawString(comboBox1.Items[index].ToString(), e.Font, brush, e.Bounds, StringFormat.GenericDefault);
    e.DrawFocusRectangle();
}

        private void Form1_Load(object sender, EventArgs e)
        {
            this.comboBox1.DrawMode = DrawMode.OwnerDrawVariable;
            this.comboBox1.DrawItem += comboBox1_DrawItem;
            this.comboBox1.Items.Add("One");
            this.comboBox1.Items.Add("Two");
            this.comboBox1.Items.Add("Three");
            this.comboBox1.Items.Add("Four");
            this.comboBox1.Items.Add("Five");
        {

        private void comboBox1_DrawItem(object sender, DrawItemEventArgs e)
        {
            // Draw the background 
            e.DrawBackground();

            // Get the item text    
            string text = ((ComboBox)sender).Items[e.Index].ToString();

            // Determine the forecolor based on whether or not the item is selected    
            Brush brush;

            // compare  date with your list.  
            brush = (text == "Two") ? Brushes.Red : brush = Brushes.Black;

            // Draw the text    
            e.Graphics.DrawString(text, ((Control)sender).Font, brush, e.Bounds.X, e.Bounds.Y);
        }