Look for clues in environment, e.g.:

        - https://bixense.com/clicolors/
        - http://no-color.org/

        Arguments:
            envars:     Additional environment variables to check for
                        equality, i.e. ``MYAPP_COLOR_DISABLED='1'``

        Returns:
            None, Bool:  Disabled

def color_is_disabled(**envars):
    ''' Look for clues in environment, e.g.:

        - https://bixense.com/clicolors/
        - http://no-color.org/

        Arguments:
            envars:     Additional environment variables to check for
                        equality, i.e. ``MYAPP_COLOR_DISABLED='1'``

        Returns:
            None, Bool:  Disabled
    '''
    result = None
    if 'NO_COLOR' in env:
        result = True
    elif env.CLICOLOR == '0':
        result = True

    log.debug('%r (NO_COLOR=%s, CLICOLOR=%s)', result,
              env.NO_COLOR or '',
              env.CLICOLOR or ''
    )
    for name, value in envars.items():
        envar = getattr(env, name)
        if envar.value == value:
            result = True
        log.debug('%s == %r: %r', name, value, result)

    return result