Another option is to identify the Collection ID of the individual pages, and then add some styles to Design > Custom CSS.
You can learn how to identify the IDs by following this guide: How to apply CSS to one Squarespace page.
This will allow you to continue using Ajax loading, for faster website performance. For example, to change the header and footer on the the-lessons-1 page, you could use:
#collection-5ea010c47e131c476b10d320 .Header--top, #collection-5ea010c47e131c476b10d320 .Footer {
background: #facfcf;
}