public static function rgb($r = 255, $g = 255, $b = 255)
    {
        // Check if values are in range.
        static::validateComp('R', $r, 0, 255);
        static::validateComp('G', $g, 0, 255);
        static::validateComp('B', $b, 0, 255);

        return new static($r, $g, $b);
    }