look fierce and talk boisterously
这忽然(sudden)发生发火(break out)的正言厉色(look fierce and talk boisterously),吓得方辰脸都青了。
正言厉色,汉语成语,拼音是zhènɡ yán lì sè,意思是形容板着脸,神情非常严厉。出自《汉书·王莽传》。