Twelve viologens, i.e., 4,4′‐bipyridinium derivatives 1 – 12, were examined for their use as electrochromic material when attached to nanocrystalline titanium dioxide thin‐film electrodes. Eight of these (1 – 4, 7 – 8, 10, and 12) are new, and their synthesis is included. The modifier compounds consist of one to four bipyridinium subunits with linear or dendritic architecture, equipped with one to three TiO2‐anchoring phosphonate groups. They are tailored for high electrochromic dynamics (large absorbance change upon reduction) and low extent of pimerization (=charge‐transfer (CT) complexation of viologen cation radicals). A new graphical method is presented for the discrimination of simple dilution phenomena and more complex structural effects on the extent of pimerization in the surface‐attached viologen layer.