public function isReadable(Color $backgroundColor, $level = 'AA', int $fontSize = 12): bool
    {
        $contrast = round($this->luminosityContrast($backgroundColor), 2);

        // Normal text
        if ($fontSize < 19) {
            return $contrast >= ($level === 'AA' ? 4.5 : 7.1);
        }

        return $contrast >= ($level === 'AA' ? 3.0 : 4.5);
    }