We propose new methods for creating color or achromatic images that are printed with classical cyan, magenta, yellow and a white diffusing ink on a metallic substrate. We optimize the surface coverages of the cyan, magenta, yellow and white inks in order to create color prints on a metallic surface that look bright and colorful under specular reflection and also look good under non-specular observation conditions. We also provide new means for the prevention of counterfeits. A first effect enables viewing on the same metallic print one achromatic image in specular viewing mode and a second independent achromatic image in non-specular viewing mode. The second effect enables hiding a pattern such as text, graphics or a grayscale image within the printed color image in one viewing mode, specular or non-specular and showing that pattern in the second viewing mode, non-specular or specular, respectively.