def hsl(self, value):
        """Setter for colour in HSL format [hue, saturation, lightness]."""

        if Colour.is_hsv(value):
            hsl = list(divide([value[0]], 360))
            hsl.extend(divide(value[1:], 100))
            self._rgb = multiply(colorsys.hls_to_rgb(*hsl), 255)
        else:
            raise ValueError("'{0}' is not a valid HSL colour!".format(value))