Transition metals complexed by organic ligands are important for energy applications and technologies, due to their ability to facilitate efficient electron transfer and catalytic processes both in the ground and excited states. Their versatile electronic structure makes them useful in key processes such as solar energy conversion, battery storage, and fuel cell reactions. Often, various excited-state processes and photophysical phenomena occurring in these systems are influenced by interactions with the surrounding environment. These dynamic effects and non-equilibrium processes occur across multiple time scales, ranging from femtoseconds to nanoseconds. To accurately capture these phenomena and the specific and mutual interaction between the TMC and the environment, it is essential to consider large systems to properly account for outer solvation shells. Reaching such extended size and time scales benefits from the use of classical force fields (FF). However, there is a significant challenge: no universally accurate or transferable FF parameters currently exist for reliably describing the metal-ligand interactions or maintaining the correct coordination geometry in TMCs, especially in their electronic excited states. In response to this limitation, here we show how a system-specific and accurate parametrization is possible using the JOYCE3.0 protocol and offers a useful tool to describe the optical properties of the squared planar [Ni(salpn)] complex (compound VI). As discussed for targets II and V, a correct prediction of the position and shape of the absorption band to electronically excited states heavily depends on the accuracy of the molecular geometries delivered by the FF. We have shown that the specific description yielded by JOYCE3.0 outperforms the one obtained by transferring general purpose-parameters that are affected by structural mismatch issues. For target VI, the comparison with transferable FFs is not even possible, because several parameters, as for instance those describing the coordination around the metal are missing in commonly available databases. For this reason, here we chose instead to validate our protocol by a direct comparison between computed and recently measured experimental absorption spectra, in which target VI revealed a clear solvatochromism.