エラーをお詫びします。実際、水は自然に青いですが、色は非常にかすかであるため、少量の水で肉眼では見えません。これは、光が通過すると、光の波長が吸収し、散らばるためです。
I apologize for the error. In fact, water is naturally blue, though the color is so faint that it is not visible to the naked eye in small quantities of water. This is due to which wavelengths of light water absorbs and scatters as the light passes through it.