G-Shock Watch 2100 Hidden Glow Mens GA-2100HD-8AER. The HIDDEN GLOW series is inspired by people's potential with luminescent parts that glow in the dark. The base colour is grey, which is reminiscent of darkness, and the face uses luminescent parts. The white accent creates a colour scheme that evokes the light that appears in a monochrome world. In the dark, the luminescent parts used on the dial stand out, creating a cool impression. A design that will accent any style from casual to work.