Most color themes highlight everything they can, ending up looking like a fireworks show.
Instead, Alabaster uses minimal highlighting. See original motivation statement.
See demo page.
Download theme file and put it wherever you need.
If your build system supports importing CSS files from node_modules, you can install hljs-alabaster as a dependency:
npm install hljs-alabaster
And directly import it in your CSS:
@import 'hljs-alabaster';