The MA was prepared by alternatively spin-coating solutions of PdCl2(PhCN)2 (4.0 mM, THF) and the polypyridyl iron complex (1: 0.6 mM, DCM:MeOH = 1:1 v/v) on FTO/glass (2 cm × 2 cm). This fully automated deposition sequence was repeated 15 times and included washing with common organic solvents (Scheme 1A, B and see Supporting Information for details). Within 70 min this protocol resulted in an electrode having the desired electrochromic and catalytic properties. The electrodes are visually homogenously coated by the dark purple MA. Such assemblies prepared by LBL dip-coating, automatic spray-coating, or by manual spin coating are known to have excellent electrochromic properties in non-aqueous electrolyte solutions of acetonitrile. The number of depositions can used to control the color intensity of the films.