Convert html in pdf,has a bug.

hello, this is my test code below.                       

   Pdf pdf = new Pdf();
   Section section = pdf.Sections.Add();          
   Text text = new Text("<span style='font-family: \"Segoe UI\"; background-color: rgb(242, 249, 255);'>TestRGBColor</span>");           
   text.IsHtmlTagSupported = true;           
   section.Paragraphs.Add(text);           
   pdf.Save(@"C:\\result.pdf");

The result can't display properly, and I find reason is use "SegoeUI" and "rgb color".I used the Aspose.Pdf for .NET 9.4.0 dll.Can you help me fixed the bug?
thank you very much