Launch VS Code Quick Open (Ctrl+P), paste ext install n3-rd.deep-abyss command, and press enter.
Override this theme
To override this (or any other) theme in your personal config file, please follow the guide in the color theme documentation. This is handy for small tweaks to the theme without having to fork and maintain your own theme.
UI: For all changes to the "outer UI", like (status bar, file navigation etc.), take a look at the Theme Color reference.
Syntax: For changes to the "code highlighting", examine the syntax scopes by invoking the Developer: Inspect Editor Tokens and Scopes command from the Command Palette (Ctrl+Shift+P or Cmd+Shift+P on Mac) in the Extension Development
Once you're happy, commit your changes and open a PR.