The terminal formatter uses ANSI escape sequences for colour. These do not work in the Win32 console.
This can be addressed by using the "colorama" package from PyPI - either by bundling or as an optional dependency.
All that is needed is
if sys.platform.startswith('win'): try: from colorama import init() init() except ImportError: pass
at the start of formatters/terminal.py.
I'll put together a pull request for this, if there is interest.