This is a variation of the Hubzilla standard theme "Redbasic". It is heavily inspired by Sean Tilley's work and his "Suckerberg" theme which you can finde here: https://github.com/DeadSuperHero/hubzilla-themes.
The theme makes use of all available theme settings and is fully colour customizable by using the theme settings. It ships with 3 default schemes, which gives you some basic colours, if you don't want to configure it yourself.
These files need to be saved in the /view/theme/ directory of your Hubzilla. You can just ftp the files onto your hub or SSH into that directory and git clone this repo.
util/add_theme_repo https://github.com/BOETZILLA/BLUEBASIC_Theme.git bluebasic