My presumption is: colors detection is done right in Job, ANSI codes should not be used in CGI output. So, Runner must somehow force Job to do it.

For variable can be used `$env` argument of proc_open(), but I'm confused if the $_SERVER or $_ENV is the right one and proc_open() doesn't like array as item (e.g. $_SERVER['argv']). putenv() is painless. Moreover, if somebody don't like colors at all, can set this variable before running the tester.