The amphiphilic organic ligand (5-octadecyloxy-2-(2-pyridylazo)phenol, PARC18) formed various colored metal complexes with transition metal ions such as Fe(II), Co(II), Ni(II), Cu(II), Zn(II), VO(II), Ag(I), Cd(II), Hg(II) in monolayers, which were confirmed by the pi-A isotherms and in situ absorption spectra of the monolayers. Well-defined LB films of the metal complexes can be fabricated by immersing the LB film of PARC18 ligand into aqueous solutions containing metal ions as verified from absorption spectra. Photoillumination can accelerate the metal complex formation process. The LB films fabricated by such methods are oriented with their functional groups inclined to the surface of the films as verified by the polarized absorption spectra measurement. Colored patterns can be written on the LB films by utilizing the photo-accelerated complex formations of the PARC18 LB film and metal ions. Different colors can be realized using a common PARC18 ligand by changing metal ions.