#monqjfa, my #nfa/#dfa, #regex library for #Java has a grep-like program as an example of the use of the library. This got a new feature resembling grep's --color option to show matches with colors, using ANSI escape sequences

ooo r='RuleParser->{c:#44ff11}'

Yes, the program is called "ooo" 🙂 Why? ... Why not?

There are more things possible within the braces, the simplest one is

'...->{c}' as a shortcut for '...->{:red}

to get the match in red.

https://harald.codeberg.page/monqjfa/javadoc/monq/Oooo.html