This post was written in collaboration with Lauren Stein (@laurlittle) and Anne McCarthy @annezazu).
Twenty Twenty-Three is here, alongside WordPress 6.1! The new default theme offers a clean, blank canvas bundled with a collection of style variations.
Style variations are predefined design options that give you the opportunity to alter the appearance of your site without having to change your theme. This means that you can keep your template structure but change the visual details of your site with ease.
For a truly diverse collection, Twenty Twenty-Three’s featured style variations were submitted by members of the WordPress community, resulting in 38 submissions from 19 people in 8 different countries. From those submissions, a curated collection of ten was chosen and bundled with the new theme.
This approach to style variations ushers in the next generation of block themes, able to harness the potential of the platform’s latest design capabilities and tools directly in the Site Editor. Since style variations don’t require any code experience, you’re encouraged to tweak and/or create your own.
Thank you to everyone who contributed. 
Useful links:
Download Twenty Twenty-Three
Twenty Twenty-Three Documentation
Twenty Twenty-Three Project Kick Off
Twenty Twenty-Three Selected Style Variations
Source: https://wordpress.org/news/2022/11/introducing-twenty-twenty-three/
