Thanks! Unfortunately, I've had to push more updates, because many frontend elements have changed even between the v0.18.1 release candidates. This may be an impossible task to maintain as a native theme option.

For now, the layout changes appear to be working as intended but most of the colour changes are not. I'm wondering if we should just pull the plug on this approach before too many users grow dependent.

I'm maintaining a version for Stylus and other CSS injector add-ons on Github. It's also available at UserStyles, and these might be the most sensible solutions as I can update them on the fly.