Hello,
Thanks for your Patience!
Since this is a Static HTML Template, the changes are required to be done manually in the CSS Files as these are pre-designed Templates that are provided with the Package and can be modified based on user requirements and their Website's content.
You can consider generating a Custom Package here: http://docs.semicolonweb.com/docs/getting-started/installation/ according to the HTML Files you need for your website and our Package Generator will sort the Files for you to download. Suppose, you need the demo-seo.html Template, simply choose this File in the Package Generator and then press the Generate button. A Custom Package will be generated for you only based on your selected file.
And then you can simply edit those HTML Files manually with some knowledge of HTML/CSS according to your needs in a Text Editor like Sublime Text/VS Code and upload it to your Servers using FTP. We recommend starting with a Localhost Setup on your personal PC/Macbook before you deploy using FTP.
Additionally, it would be great if you can please provide us with a Screenshot of the "primary title graphic" you are mentioning, so that we can provide you with more specific assistance.
Thanks for your Patience!
Meanwhile, do let us know if we can help you with anything else or if you find any further issues with Canvas.