[Zutils-bug] zgrep 1.6 doesn't support --color option

[Chris Tashjian]

I'm running zgrep 1.6 (which I grabbed and built from
https://download.savannah.gnu.org/releases/zutils/zutils-1.6.tar.lz)
on CentOS 6.9 and noticed that the color option doesn't work. I ran a
simple test vs grep to validate my suspicions:

$ zgrep --version
zgrep (zutils) 1.6

$ grep --version
grep (GNU grep) 3

$ echo cat | grep --color=auto a
cat  # correctly colors 'a' red

$ echo cat | zgrep --color=always a
zgrep: unrecognized option '--color=always'
Try 'zgrep --help' for more information.

$ echo cat | zgrep --color=auto a
zgrep: unrecognized option '--color=auto'
Try 'zgrep --help' for more information.

I checked out zgrep --help and it no longer lists the --color option.
Is this intentional?