如何在Word VSTO中更改注释的文本背景颜色？

using Word = Microsoft.Office.Interop.Word;

namespace WordVSTO
{
    public partial class ThisAddIn
    {
        private void ThisAddIn_Startup(object sender, System.EventArgs e)
        {
            ChangeCommentBackgroundColor("目标注释内容", Word.WdColorIndex.wdYellow);
        }

        private void ChangeCommentBackgroundColor(string targetText, Word.WdColorIndex colorIndex)
        {
            var comments = Globals.ThisAddIn.Application.ActiveDocument.Comments;

            foreach (Word.Comment comment in comments)
            {
                if (comment.Range.Text == targetText)
                {
                    comment.Range.HighlightColorIndex = colorIndex;
                }
            }
        }

        // 其他代码...
    }
}