Color temperature is not merely a physical parameter, but also a core "vocabulary" in the narrative of light and shadow. Through the changes of cold and warm tones, it constructs the functional logic of space (for example, offices require refreshing cool white light, while resting spaces need relaxing warm yellow light), conveys the flow of time and emotions (such as the cool white in the early morning transitioning to the warm orange at dusk), and even becomes a metaphorical symbol in culture and art (like the warm light mood in Oriental aesthetics and the cool light expression of a sense of technology). Understanding the "grammatical rules" of color temperature allows one to comprehend how light communicates with space, objects, and people — evolving from "illuminating" to "expressing", and ultimately making light and shadow a "silent language" that touches the senses.