The old site had the Solarized Dark theme - and once I saw that the code formatting on Octopress was that by default I decided to make the move. Now I can happily write Markdown formatted posts with Emacs and see an almost live preview of how it will look when published. I get to keep it on GitHub and have it in a repository.
I’ve tried to set the general colours to Solarized Light. Seems okay so far but still plenty of room for tweaking.