protected function hueToRGB($m1, $m2, $h)
    {
        if ($h < 0) {
            $h += 1;
        } elseif ($h > 1) {
            $h -= 1;
        }

        if ($h * 6 < 1) {
            return $m1 + ($m2 - $m1) * $h * 6;
        }

        if ($h * 2 < 1) {
            return $m2;
        }

        if ($h * 3 < 2) {
            return $m1 + ($m2 - $m1) * (2/3 - $h) * 6;
        }

        return $m1;
    }