def _normalize_percent_rgb(value):
    """
    Normalize ``value`` for use in a percentage ``rgb()`` triplet, as
    follows:

    * If ``value`` is less than 0%, convert to 0%.

    * If ``value`` is greater than 100%, convert to 100%.

    Examples:

    >>> _normalize_percent_rgb('0%')
    '0%'
    >>> _normalize_percent_rgb('100%')
    '100%'
    >>> _normalize_percent_rgb('62%')
    '62%'
    >>> _normalize_percent_rgb('-5%')
    '0%'
    >>> _normalize_percent_rgb('250%')
    '100%'
    >>> _normalize_percent_rgb('85.49%')
    '85.49%'
    
    """
    percent = value.split('%')[0]
    percent = float(percent) if '.' in percent else int(percent)
    
    if 0 <= percent <= 100:
        return '%s%%' % percent
    if percent < 0:
        return '0%'
    if percent > 100:
        return '100%'