You can add custom CSS in OLAP Client using the following code example. To enable CustomCss in OLAP Client, set the Autoformat property as “None" and set the CssClass property to a custom class name.
Refer to the FullBlue.css file as follows.
|Article ID:||Published Date:||Last Revised Date:||Platform:||Control:|
|3265||01/20/2015||01/20/2015||ASP.NET Web Forms (Classic)||OlapClient|