def _normalize_percent_rgb(value: str) -> str:
    """
    Internal normalization function for clipping percent values into
    the permitted range (0%-100%, inclusive).

    """
    value = value.split("%")[0]
    percent = float(value) if "." in value else int(value)

    return "0%" if percent < 0 else "100%" if percent > 100 else "{}%".format(percent)