try this:
you have to chagne listbox DrawMode property like below
private void listBox1_DrawItem(object sender, DrawItemEventArgs e)
{
var item = listBox1.Items[e.Index] as ColoredItem;
Graphics g = e.Graphics;
g.FillRectangle(new SolidBrush(Color.LightCyan), e.Bounds);
if (item != null)
{
e.Graphics.DrawString(
item.text,
e.Font,
new SolidBrush(item.color),
e.Bounds);
}
}