void comboBox1_DrawItem(object sender, DrawItemEventArgs e)
{
e.DrawBackground();
if (e.Index == 1 && (e.State & DrawItemState.Selected) == DrawItemState.Selected)
{
e.Graphics.DrawString(comboBox1.Items[e.Index].ToString(), comboBox1.Font, Brushes.Red, e.Bounds);
}
else
{
e.Graphics.DrawString(comboBox1.Items[e.Index].ToString(), comboBox1.Font, Brushes.Black, e.Bounds);
}
}