Below is an example of changing text color on selection within a custom renderer:

protected override void OnRenderItemText(ToolStripItemTextRenderEventArgs e)
  {
  if (e.Item.Selected)
    {
       e.TextColor = Color.Gold;
    }
  else
    {
       e.Item.ForeColor = Color.White;
    }

  base.OnRenderItemText(e);
  }