Past studies reported that language-specific color focality has substantial influence on the short-term memory (STM) performance of colors of the speakers of the language, which we call the "focality effect." This study attempts to clarify the continuous pattern of this effect, that is, the manner in which correct recognition possibilities and misrecognition error distances of colors, which are two aspects of the STM performance for colors, change in a gradual fashion along the continuum of color focality. Our experiment, which tests the Japanese language, finds that a U-shaped relationship exists between the focality and the possibility of correct recognition, and that the misrecognition error distance increases as the focality decreases. We speculate that the subjects' frequent and conscious employment of the memorization strategy of coding colors using linguistic categories is one important cause of the detected effect patterns.