Grey represents calm. With the darker grey shades, objects and surfaces can be placed into the background and into shadow. These colours develop their best effect in a shady environment. Iron Grey is soft, warm and expressive. It is the darkest shade of 1931. Rado True Thinline R27091612 has a Quartz movement, 39 mm case size, 3 Bar (30 meters) water resistance and High Tech Ceramic bracelet.