private function hsl2hex($hue, $saturation, $lightness)
		{
		$hue		= $hue / 360;
		$saturation	= $saturation / 100;
		$lightness	= $lightness / 100;
		if ($saturation == 0)
			{
			$red	= $lightness * 255;
			$green	= $lightness * 255;
			$blue	= $lightness * 255;
			}
		else
			{
			if ($lightness < 0.5 )
				{
				$v2 = $lightness * (1 + $saturation);
				}
			else
				{
				$v2 = ($lightness + $saturation) - ($saturation * $lightness);
				}
			$v1		= 2 * $lightness - $v2;
			$red	= 255 * self::hue2rgb($v1, $v2, $hue + (1 / 3));
			$green	= 255 * self::hue2rgb($v1, $v2, $hue);
			$blue	= 255 * self::hue2rgb($v1, $v2, $hue - (1 / 3));
			}
		return "#" . str_pad(dechex(round($red)), 2, "0", STR_PAD_LEFT) . str_pad(dechex(round($green)), 2, "0", STR_PAD_LEFT) . str_pad(dechex(round($blue)), 2, "0", STR_PAD_LEFT);
		}