grep --color=auto

• https://man7.org/linux/man-pages/man1/grep.1.html

    --color[=WHEN], --colour[=WHEN]
             Surround the matched (non-empty) strings, matching lines,
             context lines, file names, line numbers, byte offsets, and
             separators (for fields and groups of context lines) with
             escape sequences to display them in color on the terminal.
             The colors are defined by the environment variable
             GREP_COLORS.  WHEN is never, always, or auto.

See also

• ack, ag, grep, egrep, fgrep, agrep, ngrep, pgrep, awk, sed, strings, tr, tail, mtail, git grep, wc, uniq, LogQL, findstr (Windows), rg, git-grep, cut