There are other themes, but they didn't get packaged in this release. The next release will have a bunch of new themes (and I think I've convinced Chris to add my own tomorrow-night theme from https://www.refheap.coms codemirror editor to it, woot) that you can set in the command bar with 'set theme sometheme'. Solarized dark is included, but the codemirror version of that is just as bad as the default theme.