If you would like to change the content styling of an individual course, you can do that by writing custom CSS.
Note: Any CSS written in an individual course will overwrite your tenant's default CSS. Deleting any CSS from the course styling will revert it back to the tenant-level styling. For more about tenant-level styling, click here.
You can add CSS to a course by opening the Content Styles module in the inner left hand navigation bar of BluePrint:
On this page, you can write new CSS, and preview the results of what you have written. Selecting Open Default Content CSS will display your tenant's CSS, in case you need to refer to it or make a copy of it.
Publish Changes to apply any changes to course level styling in Webapp.