Text Formatting
Quick launch summary
You can now adjust text size, color, font, spacing, and more while typing in a text box in Google Sites. This significantly expands control over how individual words, paragraphs, pages, and sections look. We hope this will help you make your site look and feel just the way you want it to. If you do not yet see the feature see the information below, especially for Google Workspace sites.
Rollout pace
Rapid Release domains: Gradual rollout (up to 15 days for feature visibility) starting on December 1, 2020 Scheduled Release domains: Gradual rollout (up to 15 days for feature visibility) starting on January 5, 2021
In 2021, we will add the ability to create themes, which will allow you to easily set fonts, colors, and styles across your whole site. We'll announce on the Google Workspace Updates blog when that's available.
See https://workspaceupdates.googleblog.com/2020/12/customize-text-style-and-appearance-in.html
In a numbered or bulleted list the formatting can be changed to title, heading or subheading
One
Two
See the info from Steegle
Single line spacing
is now possible
in newly created sites
by using shift+enter.
I would prefer that single spacing be the default and double spacing be optional and I have sent feedback to that effect.
The new formatting options are being added to new sites individually. The rollout continues. If you don't have the new features you just need to be patient.