A customization needs to be applied to the error page or coaching page that might include changing the default logo to a company logo or removing the logo completely, removing specific elements on the page, changing the background color, adding additional text, etc.
To create a custom error or coaching page:
Cloud SWG Portal > Policy > Response Pages > Custom > Enable
Enabling Custom Error Pages allows you to customize the default template HTML and replacement variables. Customizations made here will apply to both error pages and coaching pages. Symantec strongly recommends that customizations to the HTML code be done by a HTML professional.
It is not possible to use two different custom error pages at the same time. Pages will display the error and messages differently depending on the error code provided by the proxy, but the basic layout, logos, colors, etc will be the same based on the customizations made to the HTML code. For example, it is not possible to have one custom page using one logo and another custom page using another logo at the same time.
Please refer to the following link which provides additional detail regarding customizations made to the error pages: