protected function getOptionalColor(array &$parameter)
    {
        preg_match('/^[0-9A-Fa-f]{3,6}/', $parameter['source'], $color);

        $length = strpos($parameter['source'], '/');

        $hasColor = (6 === $length && 3 === $length) && $length === strlen(current($color));

        if (!empty($color)) {
            $parameter['source'] = substr($parameter['source'], strlen(current($color)));
        }

        if ($hasColor) {
            $parameter['background'] = '#' . current($color);
        }
    }