IDUN MINERALS FOUNDATION - A high-pigment, silky smooth and soft formula for a natural finish. IDUN Minerals Foundation feels and looks like a powder, but is creamy to apply. The minerals easily blend into the skin to give a nice, smooth results. IDUN Minerals foundation is water-resistant and stays in place all day. The skin's undertone determines the foundation that is most suitable. If the undertone tends towards yellow/gold, it is known as a warm undertone. If, however, the undertone tends towards blue or pink, then it is known, as a cold undertone. A warm undertone is more common.