noun
cool white
A specific shade of white with a slightly bluish or cool tone, often used in lighting contexts (e.g., fluorescent lamps) to distinguish from warm white.
この蛍光灯は昼白色です。
This fluorescent lamp is cool white.
Compound of 昼 (daytime) and 白色 (white color), referring to a white light reminiscent of midday daylight.