IIRC early Turbo Pascal versions worked like that too, there was some "setup" program that let you configure colors, etc, by modifying the COM/EXE file itself.

I still run Borland's Turbo Pascal on CP/M systems, and many programs had setup/configuration programs which would rewrite binaries for specific input/output devices.

Choosing between ADM-3A or ANSI terminals by running "WINSTALL" would rewrite the main Wordstart executable WS.COM appropriately for example.