保留从组合框中选择的项目的颜色：代码附加

我有一个下拉列表（在Windows窗体中使用C＃），根据某些条件，其项目以不同的颜色显示。我无法保留所选项目的颜色。

I have a drop-down list(in Windows Forms using C#) whose items appear in different colours according to some conditions. I am unable to retain the colour of a selected item.

public Form1()
     {
         InitializeComponent();

         // cmb.SelectedIndex = 0;



         cmb.Items.Add("1");
         cmb.Items.Add("2");
         cmb.Items.Add("3");
         cmb.Items.Add("4");
         cmb.Items.Add("5");
         cmb.Items.Add("6");

         cmb.DrawMode = System.Windows.Forms.DrawMode.OwnerDrawFixed;


     }


          private void cmb_Draw(object sender, DrawItemEventArgs e)
     {
         cmb.DrawMode = System.Windows.Forms.DrawMode.OwnerDrawFixed;


         // 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;

         if (int.Parse( text) > 3 )  // condition check
         {
             brush = Brushes.Red;
         }
         else
         {
             brush = Brushes.Blue;
         }

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