Hi theInternetProfessional,
Please use the following property:
Editor.EditorWysiwygModeCss Property
Editor.EditorWysiwygModeCss Property allows you specify the location of the style sheet that will be used by the editable area. Multiple Style Sheets are supported.
Code Example:
<CE:Editor id="Editor1" runat="server" EditorWysiwygModeCss ="~/example.css"></CE:Editor>
Demo:
Regards,
Ken