I made a Stylish theme which applies a dark grey-ish look to the Documentation site, similar to how the Unreal Engine 4 Editor itself looks. The contrast between the UE4 Editor and the documentation (which is bright white by default) was getting on my nerves, so I threw this together. It’s not perfect, but it does make the documentation a lot easier on the eyes!
Install the style here: Unreal Engine 4 Dark Documentation
If you don’t know what Stylish is, check it out, it’s awesome!
I hope you find this useful, and of course, I welcome any tweaks/updates you feel would make it better!