xeleh/enhancer
A collection of utilities to enhance the Unity Editor. This is an option in Project Settings > Editor Enhancer to replace the personal Editor theme with the "Pro Editor UI theme" which is only available in Unity Plus and Pro plans. Unity defines this theme as a "Beautiful, easy on the eyes, dark UI environment". So yes, having this is pretty good. This feature has been tested with all Unity 2019.3.x versions and the latest Unity 2020.1 betas. It is a 100% legal hack, meaning no binary patching or something like that.