While checking out what #75806[1] was about I realized that there is some subtle unexpected behavior going on when coloring whitespace characters. Since they are non-printable/invisible the default GREP_COLORS='ms=1;31' is essentially a nop which mostly matters when they are the *only* match(es), like trailing spaces (as in [1]). One gets a match but no color which had me scratching my head for a while.
Long story short, I propose changing the default to include both the reverse/standout and underline capabilities. I say both because, according to [2], they are somewhat obscure and not supported everywhere. But chances are that at least one of the two is available, one would hope. Are there any ill effects when sending unsupported escape sequences? Because if not the experience out of the box would be improved; if support is lacking, no harm done. Thanks for your consideration, PW [1] https://lists.gnu.org/archive/html/bug-grep/2025-01/msg00014.html [2] https://en.wikipedia.org/wiki/ANSI_escape_code
