/usr/share/zsh/help/colon is in zsh-common 5.3.1-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 | : [ arg ... ]
This command does nothing, although normal argument expansions
is performed which may have effects on shell parameters. A zero
exit status is returned.
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