How do I change my font/colours/logo?

To change the system font, navigate to Admin > System > Configuration and expand the User interface section. A preset font can be chosen from the Font drop down and (from version 10) a custom font file (extension woff2, woff, ttf or otf) can be uploaded with the Custom font file option.

You can change more UI elements in Admin > System > Configuration > User interface too, including the header background and link colours, introduction text, dash tiles and simple search background colours, user collection bar background and foreground colours. Use the colour selector or enter a custom RGB colour code.