To customize the templates used in Automated Reports, Downloaded PDFs from shared reports, PDF exports and Notifications:
• Go from the left sidebar to Reports Center -> Templates tab.
• At the top right click Add New Template to add a new template.
You can add your custom texts and images to the header and footer boxes, add a cover letter, change colors (see how it looks in the live preview) and save when you're happy with the template content and style.
When you add a new Email Report task, set a new Notification or set PDF reports, you will be able to choose from templates you've saved by selecting them in the "Template" drop-down menu.