You can file an issue about it and ask that it be added.

Sometimes it is very useful to redirect the output to a file. Default htrace.sh produces nonprintable characters (for colors).

For disable them edit HTRACE_COLORS variable from config configuration file:

# Set output colors.
# shellcheck disable=SC2034
#   - on, off
HTRACE_COLORS="off"

This option does not affect for external tools.

I recommend to use deep color scheme of your terminal.