<img src="https://solution-community.wps.cn/uploads/post/57JSQyKqNQY.png" alt="image.png"/>

   const Range =  wpsSdk.Application.ActiveDocument.ActiveWindow.Selection.Range;
  	// or
	// const Range = await wpsSdk.Application.ActiveDocument.GetDocumentRange();
  Range.HighlightColorIndex = wpsSdk.Enum.WdColorIndex.wdGray25;

尝试用这个方法修改 没有生效；