But relying on this would be hacky at best and could easily break with various grep implementations.
Yes, thought of this before replying, but `--color=` is not [POSIX grep](https://pubs.opengroup.org/onlinepubs/9699919799/utilities/grep.html). Also the grep command is configurable, it might not even be grep, although it will need to accept the same basic options as grep does.