Cesium is one of the few metals, which really is colored in its untarnished form. It has a soft yellow/gold color, and the picture nicely shows this color. The metal is in a glass ampoule, and it was photographed while on a piece of matte aluminium foil, the latter being perfectly grey. The sample, shown here, is only small. This is only 50 mg of cesium, but even this small amount nicely demonstrates the subtle color of the metal.

Cesium metal is extremely reactive and hence, it only can be stored, safely ampouled in a glass tube, under argon.