The present invention provides mixed metal oxide based special effect pigments that can be incorporated into optically thin binder systems to produce a “metal flake” appearance that is superior to the “metal flake” appearance presently achievable using conventional special effect pigments. Special effect pigments according to the invention comprise at least 10 wt % of mixed metal oxides that exhibit the McConnellite (Cu1+Cr3+O2) crystal structure. Other metallic elements can be incorporated into the crystal lattice structure to alter the appearance effect of the pigments.