An externally ornamental golden color part such as a wrist watch case, band or bezel comprising a thermal resistance substrate and a titanium nitride coating deposited on said substrate and including in a portion of the thickness of said coating at least one member selected from the group comprising Al, Si, V, Cr, Fe, Co, Ni, Cu, Zn, Ge, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Ti, Hf, Ta, W, Ir, Pt and Au.