`-forcecolor` will force color to be on. `-nocolor` will force color to
be off.
And just because I'm a nice person, I've also added British versions of
those flags. As a treat.
This includes the bold as well.
INFO is just default, WARN is yellow, ERROR is red.
We try to automatically detect if the output is a TTY (and thus supports
colors), and don't emit colors if so. Windows 10 supports ANSI color
codes starting with a specific build, but we don't care to emit whatever
garbage Microsoft invented for builds older than that.