Solo ships three separate Google font lists that do three different jobs. After this video you will know which list to reach for and what each selection actually changes.
The three lists
- Global Site Fonts — 51 families in the current source. The chosen family is applied across the whole page wrapper: headings, paragraphs, lists, table cells, form labels.
- Heading Fonts — 26 families, applied to
h1,h2andh3only. This is how you get a display face for headings over a readable body face. - Special Fonts — 25 display faces that are imported and applied to nothing at all. You opt in by adding a class.
Every selection also gives you a class
Choosing a family does not only restyle the default elements — Solo also loads a rule scoped inside #page-wrapper named after the family. Select Open Sans and open-sans becomes available to put on a single heading, a block, or a paragraph in CKEditor. That is the whole point of the Special Fonts list: import a face once, then apply it deliberately where it belongs instead of everywhere.
Serving the files yourself
There is a checkbox marked Tick this box to load Google fonts locally, and the label narrows it honestly: Global and Heading fonts only. With it ticked Solo swaps its external stylesheet libraries for local @font-face files that ship with the theme. Special Fonts are always requested from Google's servers, so if your goal is zero third-party font requests, do not use that list.
Where all of this lives
Everything is in the Libraries & Fonts section of Solo's theme settings, split into vertical tabs: W3.CSS Library, Font Libraries, Global Site Fonts, Heading Fonts and Special Fonts. The same section carries a Font Awesome selector offering none, 4.7 locally, or 4.7, 5.15.4 and 6.5.1 from a CDN. Solo runs on Drupal 10.1, 11 and 12 with PHP 8.1 or newer — see the Solo theme page or the introduction in Looking for the best free Drupal theme.
If you would rather have this set up for you, Drupal theming services covers the work, and recent projects show the result.