Based Linux Plymouth theme (script module), generated by based-brand.

Install this directory as /usr/share/plymouth/themes/based-linux/ (the .plymouth
descriptor references that absolute path) and select it with:

    plymouth-set-default-theme -R based-linux

(the plymouth overlay's build hook does exactly this given theme: based-linux).

Asset the build pipeline must supply into this directory:

    logo.png    brand logo, contain-fit (e.g. 380x380); the script
                centers it above the progress dots

Everything else (background gradient, progress dots, prompt and
message text) is drawn from the base16 palette by based-linux.script.
