GitHub Pages supports the following themes:
- Architect
- Cayman
- Dinky
- Hacker
- Leap day
- Merlot
- Midnight
- Minima
- Minimal
- Modernist
- Slate
- Tactile
- Time machine
See the GitHub Pages help documentation for instructions on how to add a theme to your GitHub Pages site, and follow The GitHub Blog for information on additional theme support.