how can I show a colored textbox in a string

Hi ,
I need to show a colored textbox in a string ; I used the above solution but it didn't work
System.Text.StringBuilder sb = new System.Text.StringBuilder(); sb.AppendFormat(@"<div style='width:10px;height:10px;background-color:{0}' ><div/>", System.Drawing.ColorTranslator.FromHtml("#8db3e2")); Name= h.Name + sb ;