As a four-character idiom (成语, chéngyǔ), 大惊失色 is part of a rich literary tradition in China. These idioms often distill a story, historical event, or a vivid image into a concise phrase. Using them demonstrates education and eloquence. The concept itself emphasizes a holistic view of emotions, where a strong internal feeling (fear) has an undeniable external, physical manifestation (paleness). This is a common feature in Chinese descriptive language, which often favors “showing” over “telling.” In Western culture, we have similar expressions like “to go white as a ghost” or “to be scared stiff.” However, 大惊失色 is more of a standard, almost default literary description for this specific reaction. While “white as a ghost” is a simile, 大惊失色 functions more like a verb phrase or an adjective describing a state. It is the action and the result all in one. You wouldn't just say someone “did” 大惊失色; you'd say they heard the news and (were) 大惊失色.